I encountered this bug last night, but it seems to be repeating....
In a mission, find a locked chest. Attempt to disarm any trap with the bomb diffuser. No bomb, so attempt fails. Unlock chest with lockpicks. Chest opens. Empty chest (usually empty anyway.)
Now, when I close the item window for the chest, the chest doesn't close. It doesn't go away. If I attempt to open it again, it says it is locked. But no amount of lockpicking will open it again. If I go find another chest and open it, I can go back to this chest and lockpick it again.
I will test this more tonight....