Bug that allows to make a copy (make a duplicate) of an item (anything that you can put in Grindstone)

playing on realm It’s possible to duplicate items using grindstone, just put at item in grindstone and click fast on the “result” item you are creating, and i’m getting a duplicates...  tried with enchanted books, unencanted armor... and got a lot of same items... so easy way to get some extra  elytra wings