In this post I am showing what happens when all plugins are disabled:
01-1-all plugins inactive
Just to show no plugin is enabled
In the Twenty Twenty default theme you can see the admin bar, as expected for admin
In the Twenty Twenty default theme you can also see the admin bar for a normal user (testuser)
In this post I am showing what happens when all plugins except wpForo are disabled:
02-1-Only wpForo plugin active
Just to show wpForo is the only plugin that is enabled
Once again, in the Twenty Twenty default theme you can see the admin bar, as expected for admin
02-3-testuser-adminbar NOT visible
This is where things change: a user who is not admin, will see extra padding where the admin bar would be. This happens when "Show Admin Bar for Members" is set to No.
Nope, did not solve this :/
this is a very old problem with Wordpress when the adminbar is hidden
But the adminbar is not hidden, that's my entire point. If you check this post above, you will see that WordPress itself behaves normally when all plugins are disabled.
But when you activate only wpForo, with the "Show Admin Bar for Members" set to No, that's when you notice the problem.
How do you explain it?