Categories are not shown in BE when user / group has "category_perms" set
When a BE user or a BE group has a sys_category permission setting there are no cal-categories shown in backend when editing a cal event.
I'm not using sys_categories with cal.
I tried to play around with cal's access control but it had no effect.
I'm using TYPO3 7.6.4 and cal 1.10.3.
Any hints for that?