Its the unit, it was failing on the last trip even with the phone disconnected.

It may have used bluetooth but the USB cable was unplugged so its not android auto, it does it after about 90 mins driving. There should be no way for a BT device to cause a master unit reset, drop the connection yes but not force a reboot.

One last thought, look in messages to make sure there is not a pending update "stuck" there. some territories do OTA updates for a lot of stuff, even major software updates.

If it's not that then all you can do is take it to the dealer and ask for a full re-install of the software. Or a new infotainment unit.