2019 is350

I upgraded from an iPhone 7 (iOS 12) to an iPhone 11 (iOS 13). Before the phone upgrade, my car would ignore any conversations that had the "Hide Alert" setting activated, but now with the new phone, the car is alerting EVERY text message that comes in, even if the conversation is muted. You can imagine how annoying that is if a group chat picks up in conversation...

Is there anything I can do on my end or do I just have to wait for Apple or Lexus to fix this issue?

 

Welcome to the forum!

I'm assuming that however you transferred your data from your old phone to your new phone, you wiped the old phone from the car and the car from the old phone...and the new phone if it transferred the Bluetooth profile for the car.
I'm not sure if Apple does this, I'm a Samsung user and they transfer the Bluetooth profile as well.
If you didn't start with a fresh pairing, then that's step number one.
If you did, then I suggest erasing both and pairing again...sometimes it takes a few attempts for the pairing to go right.

And there is nothing for Lexus to fix here...in describing your issue, the vehicle is a constant, meaning the Bluetooth on the vehicle has not changed...the variable is the software of the phone, and the phone itself, that changed.
So if anyone has to "fix this", it would be Apple. Unfortunately infotainment systems seem to be primarily designed to work with Apple products, however it seems by the threads that Apple users have all, or most, of the issues...and it's always after an iOS update.

 

I had this EXACT same issue (I was going crazy with the group message alerts)..I was able to fix it. First you need to 'delete' the phone from the car. Then under bluetooth on the phone click 'forget this device' on the Lexus IS or CarAccessorySystem connection..repair and you should be good to go.