Some brief notes on setup and config for software I use.
Quit Betterbird if running. In the folder ~/.thunderbird/[PROFILE]/calendar-data, rename the files cache.sqlite and deleted.sqlite. Run Betterbird, and the calendar should start populating itself from Google Calendar.
To find out which profile directory you need, run betterbird -p and study ~/.thunderbird/profiles.ini.
This is because you've got ProtonVPN installed! Disable the extension from the extensions manager, make sure you can connect to the web, re-enable and disconnect it. To prevent this from happening, disconnect from the VPN before closing the browser.
Just give it a couple of weeks; it usually sorts itself out. No idea why this happens.
