Unable To Delelte Old Phones/add New Phone In Bluetooth

[bluebird11]

I have a 2008 ES350 and cannot keep a new phone paired or delete the old phones once car is shut off for 1 minute and restarted. Every thing is fine initially. You can turn the car off for 30 seconds and everything is still fine. But leave the car off for more than 1 minute and everything reverts back to the way it was. I saw several posts on this same problem several years ago. If anyone had this problem, what was the fix for this issue? My dealership has been unable to solve the problem.

Thanks,

bluebird11