well then your usergroups are not correct in category permissions.
I would suggest you under admin => edit usergroups refresh your usergroups from
vb. Now remember we cache group settings that already exist so group names etc will not change on old groups. if you have renamed groups in
vb and photopost has old names you may not be lining things up right possibly. Correct any group names as our usergroups are displayed numeric 1-100 etc
You can then reapply permissions. You can see your issue by narrowing things down by user seeing what group they belong to and checking in photopost say what usergroup 20 is set to etc.