Does the wireless remote (Key FOB) go into a sleep mode if you don't use it for a couple days? I've noticed a pattern, if I don't drive the car for a couple days, the car won't start with the wireless remote (while pressing the car's start button with foot on the brake pedal). I don't see anything in the user manual about this behavior.

When it fails to start, I can hold the key FOB up to the start pushbutton (as though the FOB battery was weak) and the car starts. Or I can keep pressing the car's START button 2 or 3 times, and the car finally starts. It's as thought I am "waking up" the wireless remote. This has intermittently happened since I bought the car in 2023. I changed the battery in the remote even though I never got any kind of low battery warning indicator. It always seems to happen when the car has not been driven for at least two days.

I may switch to the spare remote to see if the pattern repeats. It would be a really hard problem to show the dealer since it's so intermittent, I'm not sure it happens every time the car sits unused for a while.

 

It sounds like you are using the key fob to start the car, which can be done, but the distance on that is pretty short, I would think, and would be a factor of, among other things, the battery strength and the distance. I have also read here that remote starting with the fob can be unreliable. (If you have to hold the fob up to the start button to start the car, that's an indication that the fob's battery is weak or even dead.)
I've never used the fob for that (I don't use the fob at all since I got the skinny card) but I start the car remotely from my phone often, and that can be done from anywhere you have a cell phone signal and when the car is in a spot to get the signal. I start it from inside offices and gyms, for example, and it's a nice feature when the weather outside is less than delightful.
I think you have to keep up the subscription, but almost all of the little fun extras we come across cost extra.

 

I can see why my wording was confusing and I edited my first post to hopefully clarify. Lexus refers to the key FOB as a "wireless remote", which can be used to start the car remotely, but that's not what I meant. The Key fob is in my pocket and I use the "Start" pushbutton in the car (while pressing the brake pedal).

 

Do you leave your ES unlocked for those long non-use periods, allowing you to enter the vehicle without requiring an electronic key to unlock the driver's door to enter the vehicle?

If so, your electronic key may have stopped functioning to reduce battery depletion. On page 107 of the 2024 LEXUS ES250, ES350 OWNER'S MANUAL USA AND CANADA ONLY, this was added starting with the 2023 model year:
The reason for the unlocked question is that the smart access system also goes into a battery-saving mode that can cause a delay in door unlocking while the system wakes/powers up when you grip the door handle to unlock the door(s). That unlocking delay may be hiding a wireless remote functioning wake-up delay. So, if you're leaving the driver's door unlocked, your wireless remote may not be getting woken up prior to your trying to start your vehicle, and what you're experiencing is the side effect of a wireless remote wake-up delay.

On page 372 of the above-referenced Owner's Manual, there is a troubleshooting "When the electronic key does not work properly" section. Of the three items listed, this one:
appears to be the closest one that may be causing the behavior you're describing.

Although it isn't mentioned in the Owner's Manual that I can find, if that's the cause of your starting troubles after a long period of non-use, you might try the same wireless remote wake-up procedure as used when the wireless remote has explicitly been put in battery-saving mode. Which is to press a wireless remote button to wake the wireless remote up. I'd use the UNLOCK button since that's the state you want your ES in when you go out to it and get into it.

If all else fails, there's also the following NOTICE:
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