Describe the bug:
Infinitely spinning millstone as long as it has any items in it.

To Reproduce:
Place millstone.
Put any item in the millstone that can be milled.
The millstone can be rotated indefinitely until the items received are picked up.

Expected behavior:
After all items are mulling, millstone is no longer possible to rotate.

Additional context:
I was also able to get an infinitely spinning millstone without any items, but I could not repeat it again. NBT:
inv:{Items:[{id:"minecraft:air",Count:0b},{id:"minecraft:air",Count:1b},{id:"minecraft:air",Count:1b}]},result:{id:"minecraft:air",Count:1b},activateTicks:40,ticks:0,rotation:1.5708114f,active:0b,secondResult:{id:"minecraft:sugar",Count:1b},secondChance:0.10000000149011612d

Version:

• Mod version 1.3.2
• Minecraft version 1.16.5