there is a know bug that does this when you put corrupt items in your bags

[Linked Image from gog.com]

the 2 icons and lack of a split items option when you right click them is the best tell... dump these items and walk away, don't sell them, sort them or place in containers

this is a basic game code error... the only fix is to load another save game from before you tried it

Luke Skywalker: I don't, I don't believe it.
Yoda: That is why you failed.