Steps to reproduce:

1) Get a banner pattern.

2) Put it on the empty slot of the loom.

3) Remove it from the slot.

4) Observe the slot.

Expected:

After removing the banner pattern, the slot should immediately return to an empty state.

Observed:

The banner pattern is duplicated fakely and stays still in the slot visually. If you close the GUI of loom and reopen it, you should find it back to the empty state.