Should be fixed in most recent version of the app, please update if you haven’t already.
Viewing post in fixing Itch.io app doesn't launch on Ubuntu
The above Chrome suid fix needs re-applying after any update to the Itch app.
To avoid this, https://github.com/itchio/itch/issues/3250#issuecomment-5019305423 has a workaround that survives updates.
Per my comment, ideally the Itch app would ask to make this change when it's first installed.