Move the Duct tape
The Double Halberd counts as being adjacent to itself because of the tape
Isn't it just supposed to pass on effects? The weapon doesn't give anything else an effect, it just can't be next to a weapon, which it's not. If I had to guess what was causing this bug, they probably use an invisible effect to track weapons being adjacent to others, and this invisible "technical" effect is being treated like a regular effect, despite not being listed in the stats at all.