I don’t know if related, but immediately the last two MacOS upgrades I was unable to get my networking to work. I could connect to Wi-Fi / Ethernet / Hotspot. But nothing would actually connect (e.g. browser, pings, etc) , not even to my router.
The fix both times was to open the Mullvad VPN app just once and everything worked again. No idea why just opening the app would fix the issue.