Equipping a quiver full of arrows into the Quiver Accessory slot displays no arrows in its inventory while holding the "Quiver" hotkey and attempting to cycle arrows.

While the Quiver is in the inventory, it works as expected.

Support for 1.20.1 is being dropped and I recommend investigating if the issue exists with this mod on 1.21.1 if possible with either reopening this issue or creating a new one.