If shears are in a dispenser and it is activated, shears will be dropped by the dispenser instead of being used.

In version 0.2.1 in minecraft 1.15.2

Can confirm. A sad consequence of how dispenser behaviors are registered.

I tried adding a new one for Shears if they're facing the Cutting Board, but the registry dislikes dealing with more than one behaviour, causing it to cancel out the vanilla one.

I'm looking into a workaround, but honestly, I might just remove the behavior from shears for now. All it does is process saddles anyway. x)

@LordGrimmauld fixed it, and improved the dispenser registering on commit f9fcb30.