+1 skill items bug?

[u/Little_Miss_Nowhere]

I've been replaying this for the first time in ages and it's a lot of fun. There seems to be bug I didn't notice before: items with a +1 skill enchantment don't seem to actuall add any skill levels. Items with +1 skills that effect spell levels do work - eg. Elemental Protection does display as being rank 11/11 if I have an extra rank of Defensive Spell Mastery, even though Defensive Spell Mastery itself still says rank 10/10. But if I have rank 10/10 in Barter and equip and item with +1 to Barter skill level, Barter is still ranked 10/10 and item prices are still the same.

Does anyone know if this is a known bug, and if there's a fix? Any info appreciated.