Is the ringer switch in the off position?
No sound on iPhone

Is the ringer switch in the off position?
No, I do that quite often so it’s the first thing I check.

I assume you've checked the phone's volume level and the app's sound setting.
You could try deleting the app and reinstalling.
The last week, during live games, there is no “move” sound. I can’t find a setting that has been changed anywhere.