I think it’s important to remember that we’re trying to help you – the issue you’re having in complex, so it’s going to take some testing to figure it out.
Since you’re experiencing the issue in your Dashboard, plugins like Autoptimize aren’t going to fix anything as they optimize the front-end.
It also means it’s not the CSS and JS files you initially posted, as they are only loaded in the front end.
So if you’re willing, here’s a plan to figure out what’s going on.
1. Deactivate GP Premium – does the issue still exist?
2. Deactivate GeneratePress – still happening?
3. Install Query Monitor – you can uninstall it when the issue is resolved, it will simply give us more information as to what’s causing the issue.
Looking forward to hearing back.