locked weapon sets get unlocked when picking up off-hand from ground

It happened to me a few times for example when I picked up a normal rarity shield from the ground in a map,
that my locked weapon set (not where the actual weapon is, but where the copy of it is) would get unlocked, and the shield would equip and my skills would be unuseable, that are linked with that weapon set.


Edit: And I know there is an easy fix for that - to disable auto-equip, but it still looks like a bug.