Categories not hidden in Metabox

I have a fresh install of WP 4.7 with UAM 1.2.7.6, Created 6 user groups (in which only group users have read and write access), assigned the groups to various users, created several Post Categories which are assigned to one or more groups.

When writing a post users should be limited to only assign Post to Categories assigned to Groups they are member of. Unfortunately, the Category Metabox still shows ALL Categories. When selecting the wrong category users will get a “Access Denied” message and the post they’ve created is unrecoverable.

I’ve already tried al kind of combinations of the settings but with no result. Probably I’ve missed something…..please help me out!!