It has to be some type of computer issue or the Nav screen would just go blank vs fading away. I don't think the tech(s) have reset the system otherwise my settings would have been gone when I picked it up both times its been in the shop for these problems. I do have VPN activated but that shouldn't be the issue because my iPhone paired with the loaner - a 2025 RX350 - with no issues and I had it for several days. I drove this car for months without these problems with the same iPhone pairing up every time.

Resetting the power will only reset volatile memory. It will not impact non-volatile memory. Same with computers where the bios/uefi is stored in non-volatile memory so you don't have to set up the hardware each time you power cycle the computer. So my question is this, what kind of memory is used to store these shift points? I just have to wonder if it is really as simple as power cycling the entire car...

I’m don't know about the 2025 RX350, as it's a newer platform that's very different from the ’23+ ES. However, I can confirm that on Android devices, VPN usage can interfere with connectivity. Android initiates the connection via Bluetooth, but once paired, it transitions to Wi-Fi, leveraging the network stack to communicate with the infotainment system. Activating VPN software introduces additional network routing, which may disrupt the communication process. For example, connecting to my home network using OpenVPN while driving will interfere Android Auto on my ’23 ES every time.

To troubleshoot, I recommend first temporarily disabling the VPN on your iPhone to rule it out as the cause. If issues persist, consider performing a Multimedia System Reset to eliminate potential software glitches on the head unit.

The fading effect, as limited to the map’s center position and not the entire screen, might be due to the system’s inability to refresh map data in real time. That could be caused by DCM or phone network signal issues. The center point remains visible because position is determined by the GPS antenna;,but the map data (if not stored locally on the infotainment system) could be downloaded from the cloud. If there’s no active connection because of network issue, that could explain the behavior.

That’s my best guess, as I’m not familiar with the technical details of the navigation software.

Correct and if there is a glitch in the volatile memory it will be removed by reset. The memory embedded in the micro or eeprom will not be affected bringing system back to original state. If that is where problem lies then replacement only. Strange after battery replacement it seemed to have resolved which meant low voltage to micro at startup causing glitch.

I think that under Georgia law you have 24 months (or 24,000 miles) from purchase to file a Lemon Law complaint, assuming the vehicle was purchased in Georgia. So, unless it clearly doesn't qualify, even if the odds of prevailing don't seem that good, it might be a wise tactic to file a complaint online before the statute of limitations runs. That is just to preserve your rights in case it might appear to be advantageous in some way at a future time.

A couple of anecdotal and speculative thoughts to add...

1. RE: the iPhone hiccup of not connecting after you had the loaner, I wouldn't worry about that. For my job here at ClubLexus, I drive upwards of 20 different (maybe more) Lexus and Toyota vehicles every year, and random CarPlay hiccups are pretty common. It's unclear to me if this is an iPhone issue, a Lexus Interface issue, or some type of combo. But since I get random CarPlay gremlins across all brands of new vehicles that I'm fortunate to test, it seems more like an Apple issue. I could be wrong, but I don't think that's a symptom here.

2. RE: the Lexus Nav maps fading to white, it looks to me like the Nav system is losing access to data or not caching something (I've experienced similar on smartphones when losing cell phone coverage). I don't know exactly how this system works, but is there anything around there that's problematic for cell phones or GPS interference?

EEPROMs

https://en.wikipedia.org/wiki/EEPROM

I drove the car again today. My iPhone wouldn’t connect. I cut off Bluetooth as the technician suggested, turned it back on, and it still wouldn’t connect. On my iPhone it showed that the car was connected in the settings. The car showed it wasn’t connected. I took pictures and sent them to my Service Advisor. After I got finished at my destination I got back in the car and my iPhone connected with no issues and everything worked as it should on CarPlay.

If Lexus tries to blame this on my iPhone 14 they will need to explain to me why this same iPhone has worked flawlessly on the 2020 Chevrolet 2500 that I sold to buy the Lexus, my wife’s 2020 GMC Denali, my 2021 Corvette, and my wife’s current 2025 BMW X5. The survey in this thread posted earlier indicates my problem with the Lexus electronics is not unusual.

The DCM is used for more than that.

From page 175 of the 2024 LEXUS ES250, ES350, ES300H MULTIMEDIA OWNER'S MANUAL USA AND CANADA ONLY:
And from the Lexus support article LEXUS INTERFACE DRIVE CONNECT CLOUD NAVIGATION:
Although the details are fuzzy on how large a coverage area of local map data is downloaded from the cloud per refresh, how often the mapping data needs refreshing, and differences between data stored for active route guidance and no route guidance navigation system operation, it seems clear that navigation mapping data is temporary with local area limited scope and requires refreshing from the cloud as the vehicle proceeds into new territory.
Based on the photos FastDawg posted above, I agree. As his ES moves forward into new map display territory, the map display for the new territory being travelled into is blank/white, which is consistent with the navigation software not having any map data for the new territory to display on the screen.

So, the diagnostics questions are: what are the possible causes for the vehicle's navigation system not having map data to display for the new territory being travelled into?

Based on a previous FastDawg post, his iPhone is using the AT&T cellular network, which is the same cellular network the 2024 ES DCM is using for outside world communications with Lexus servers for data such as Cloud Navigation map data. From the few photos showing the DCM reception status icon (in the upper right corner), it looks like the DCM has a working cellular network reception status. Since he hasn't indicated otherwise, I assume he isn't having any iPhone cellular network connection problems at the same time the navigation map issues are occurring. Although one can't completely rule out a cellular network data communication problem with the external world, I think it is unlikely to be the source of the problem.

The photo with the:
dialog raises a suspicion that some sort of issue in the device connection area might have something to do with stalling the map data refreshing from the cloud. (Based on Bluetooth network glitching issues in my 2019 ES, Lexus networking stacks software is on the fragile side. Figuring out the source of a possible networking problem like this one might be and how to avoid it requires quite a bit of thought, trial and error, and a heap of luck.)
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Check to see if the vehicle has software version 1040 or later.

Thank! Very informative. That was exactly my though logic after looking at the pictures the first time.

My best bet is either: 1) the DCM module, 2) specific iOS app or phone settings or 3) infotainment system reset needed.

DCM: My DW experienced a similar issue with her '19 RAV4 where the microphone suddenly stopped working for calls. Dealer said it was possible a defective microphone. I noticed the SOS indicator was lit red. After some research, I found reports of a DCM freeze causing various infotainment malfunctions. The recommended fix was to disconnect the battery for an extended period to reset the module. I left it disconnected overnight, and it resolved the issue. Fortunately, unlike the ES, this didn’t reset the rear camera settings. Maybe a DCM glitch that need a reset or replacement?

iOS: I don't know about the iPhone but 100% that in Android a VPN app/connection could interfere with infotainment connection and network stack even with a full bar cellular connection. Also sometimes phone settings could cause similar symptoms on some head-units. There are a lot of reports even on other brands here there's a compatibility issue with the specific infotainment/brand but works 100% in other cars. So a Lexus compatibility issue with an specific user iPhone/Android configuration is not necessarily something irrational even if it works on other vehicles. Lexus certainly could improve compatibility with new a software update.

Infotainment: Finally, sometimes a simple system reset is all it takes. I had an issue trying to link my wife’s profile to our Lexus infotainment system, and nothing seemed to work; not even getting the QR code to display. I’m very tech oriented and very good at troubleshooting; but couldn't figure that out. In the end, I delete all user profiles and, just like that, it started working again. Go figure.

I think latest version for '23+ is v2050 from Feb, 2024. Version 1040 is an older one.

Unfortunately it does not appears Lexus is any good at frequent software updates. :sad:

Agree. My car is a 2024. This shouldn’t be an issue.

My iPhone with AT&T cellular service works fine when the Nav system is showing errors. When it was showing an error connecting I called my wife to check that. The call went through fine - just not through my car’s speakers.

I was supposed to hear from my Service Advisor yesterday but she didn’t call. I’m hoping they aren’t trying to avoid replacing something expensive. Georgia is a hands free state. If a LEO observes a driver on the road with their cell phone in hand that’s an instant ticket.

Your relationship with the dealer should help with you providing info but generally they have to see the problem before any parts can be replaced. Once they see a problem does exist parts will be replaced until fixed. I don't think this is a data problem because you said it still happens when a route is set and the downloaded route is in memory even if offline from what I understand. How long after battery replacement did this problem come back?

While it's highly unlikely your vehicle is running version 1040, there's a chance it launched on the older software if it was manufactured prior to the v2050 release. Anyhow, as of today, I think the infotainment system should have already notified you of any available updates. But it does not hurt to confirm.

Although it's technically possible to have voice service without data, I'm 99% confident that this isn't a phone cellular coverage related issue. Any issues with online data are most likely caused by VPN apps or particular mobile network settings.

I suspect probably DCM module if not related to phone/info reset pairing. @Cut-Throat recently posted about an issue HERE where the doors wouldn’t lock or unlock via the app, despite remote start functioning properly. It turned out to be a DCM fault, and it's scheduled for replacement in the coming weeks. A DCM reset could explain why it worked for you a while ago when they changed your battery.

Either way, I’m eager to hear what the final fix turns out to be. Good luck!

Edit: As @grp52 pointed out the DCM (Data Communication Module) is a very complex unit that provides a bridge between the ES internal systems and network connected services, including but not limited to the infotainment system.