Hello @Simon_Damiaens!
I am surprised that steps 1 and 2 didn't work 
Could you share what you did for those steps?
Retool has both an option to ''hide query status' from users as well as a tab in the advanced settings to disable a query when a boolean value equates to true.
Check out this form post that outlines both of those here!
If they are not working then we might have a bug, which I can hopefully reproduce and send to our engineering team to fix 