When using the loom to craft multiple banners of the same type, left clicking with another banner in the banner slot will cause graphical glitches. The special banner pattern in the pattern selection will appear for a split-second then vanish. The banner that is crafted will vanish but can still be interacted with. The banner preview will vanish as well. The finished product and the preview will reappear after crafting the 2nd time but will vanish after the 3rd time you craft.