[Fixed in 1.13] Not receiving exp from furnaces

I set up a mega smelter to heal my tools with mending. I was able to heal a diamond axe one time, and now I do not receive experience from any furnace I extract items from. This includes furnaces without hoppers, as well as furnaces with hoppers that have been turned off so I can pull items out of the furnace. This is happening with furnaces and blast furnaces