I created a thread 3 years ago about a similar problem : Dorico 3.1 : Instrument names in French + Shortcut issues with MacOS - #19 by francisb
To me it happens several times a day. The only fast solution I found is to switch from the French Canadian Keyboard (the one I’m using normallY) to the English one and switch back to the French Canadian. Then it works fine. I have to this about 5 times per hour (sometimes even more, like at each minute). I hope someday it could be fix but it seems I’m the only one having this issue 