Ok I think I need some help because I am not a webdev. I have a Wordpress installation where the block editor freezes the browser (probably since the update to 5.6). Its not the plugins (I deactivated them all), and not the theme (tried multiple), and not a specific post, and it happens in both Firefox & Chrome. It is not a general wordpress problem, because I have other installations that work fine. How to I get this fixed?
Oh wow I fixed it. It was a plugin after all - a user role editor. As long as a user had that custom role it did not work, no matter if the plugin was actually active. Changing to a default role and disabling the plugin was the solution.
@ConnyDuck Smells like a script is hanging due to a recursive loop
@ConnyDuck Memory leak? But that is my very uneducated guess.
The performance inspector in Firefox says there is a "DOM-Event" going on forever. What does it mean?