The December update for the Google Pixel 6 series may be breaking signal reception
Since installing the December update, there have been multiple reports of Pixel 6 series phones suffering from poor signal reception. Most of these reports seem to be coming from Europe, although it appears some users in the US and Canada have also faced similar issues. Supposedly, after installing the update, signal reception essentially flatlines, with some users claiming zero network bars indoors, leaving them with the sole option of using a Wi-Fi network for internet access.
Interestingly, though, this issue may not be as prevalent as one would think. The r/Android thread where it was reported, for example, also has a multitude of users in Germany, France, Italy, and other European countries claiming that they face no such issues after installing the update. Either way, there's a non-zero chance that installing the December patch may break your Pixel 6 series phone. Make of that what you will.