https://support.google.com/pixelphone/thread/143183382/december-2021-update-paused?hl=en
Google has managed to mess up the only thing a phone should be able to do which is place/receive calls.
The fix won't be coming until late January and the current solution is to roll back to the November update which requires a factory reset.
How did software development, especially in a company as big and as renowned as Google, get so broken?