Custom items reading as vanilla at vanilla villagers trades

Hi!

We faced with the issue, that item, which is based on possible tradable item, still can be traded at vanilla villagers.

Testing item:

MyAmazingEmerald:
  Id: EMERALD
  Display: "I bought it for 1000k of dimaonds"

Spawn vanilla villager and give it profession. If it has emerald trade - it will accept it. Check video for more defails: https://streamable.com/qfzle5

If you need more details - please contact me in discord: @DezForse