I launched the browser with the proposed command line.
I was very surprised to notice that the problem totally disappeared!!!
So I relaunched the browser from the app launcher to compare and no problem anymore too!
As if something in the browser config has been reset by this command.
In addition I noticed that copy/paste cursors were unusable before and now it has also been solved by this manipulation.
Hope it helps to understand the problem origin.
At least, it’s a workaround!