I also had various language problems. Solution: Set the language to German (Germany), German (Switzerland) causes the problems.

I had exactly the same problem, a repeated reset did not help me.
I received another solution from Google support that solved my problem: Apart from German, select a second language (any language), disconnect the device from the power, wait 1 minute and reconnect it to the power. After that, you can remove the second language again.

My hub from Galaxus was a return that happened to be set in Spanish. I did a factory reset and everything was in German. Here are the instructions from the user manual:
Press and hold both volume buttons on the back of Google Nest Hub simultaneously for approx. 10 seconds