Android Auto suddenly stopped working and no longer starts

So I've had Android Auto running for a bit over a year now. I have AA 1.08 installed on my 2015 Mazda3 with firmware 59.00.441A-NA. Just yesterday I upgraded my Sony Xperia X Compact from Android 7.1.1 to Android 8.0.0. I had to reboot the phone and CMU in order to get it to connect the first time, but then it worked normally heading home from work and then again heading to work this morning. Then all of a sudden it has completely stopped working at all.

I've tried rebooting both the phone and the CMU several times. The CMU never seems to get a signal to start AA. Even if I manually start AA from the CMU, it just sits there with a blank window never doing anything. I've tried starting the headunit server from the AA Developer options on the phone, enabling and disabling USB debugging, clearing USB debugging credentials, and clearing the list of authorized cars in AA. None of it seems to make a difference.

I did just update the Google app, but when I try to uninstall the latest updates, AA fails to launch on the phone and then downloads the latest Google app anyway. That's the only other thing I can think of because it worked fine after the Android 8.0.0 update.

Has anyone else started having problems like this recently?