I have a field (checkbox) that is inexplicably inaccessible by most users even if they're in the profile that allows them access to it. I've checked the field level security and it says it's editable by all profiles, and accessibility says it's editable in all layouts. Even if two users have the same profile and role levels, one will be able to edit it and the other will not. I tried cheating with a permission set where I explicitly allow editing of that field only, but it didn't help at all. It's bad enough that even the admin isn't allowed to edit it. As of right now I know of only three users that are capable of editing it and even blindly matching other users to their roles/profiles doesn't help. I tried checking with perm-comparator, but nothing odd stood out for me.
Is there any other place I should be looking into to try and figure out why this one field is so darn hard to edit?