Tag Manager debug console not loading

I have installed MTM on my website but the Debug Consol is not showing.
Maybe I have done something wrong somewhere.
I already got to the FAQ: Why is debug console not loading for me?
But does not help.

Hi @nicolassan ,
Are you sure you call the MTM container in your page?
Are you in debug mode? (MTM debug mode activated, querystring parameter set, etc.)
Can you check if there is a JavaScript error in the page?
Can you check if the debug section is maybe present in the DOM but just hidden by CSS for example?