Since my 965 updated to 16.17 it has (intermittently, unpredictably) gone into a frozen state where the watch is unresponsive to every button press or screen touch that I have tried. The first time this happened the watch was charging and the screen became completely black, but unplugging the charging cable had no effect. The watch recovered and began responding a few hours later for no obvious reason.
The next time it froze, the screen was displaying my training status. Again no input had any effect. Then I connected to the watch from my phone with the Garmin app to check the software release. I also synced the watch, and suddenly it started responding to input again.
This didn't happen before the update to 16.17 so it appears to be a new bug.