Maybe you unplugged the device before unmounting it leaving the filesystem in an odd state? Next time it fails to auto mount check /var/log/syslog for recent error clues.

It is probably all the google telemetry and monitoring and wifi scanning to map your location for sale that is running in the background. I plan on getting a pixel 7a soon but will immediately wipe the google junk and load grapheneos. Apart from getting rid of all the spyware this also doubles the battery run times.

I wouldn’t trust a google phone telling you that a competitors browser is problematic