This issue only occurs when fabric api is installed and when on a specific world. I cannot reproduce it on any other worlds and I have also tried all 1.15 fabric api versions, with no change. I doubt this is a client-side problem as the client is on the vanilla game, it doesn't occur when the world is run locally or when the server is running without the fabric api.

Try deleting the the fabric registry files in the data folder of the world. Make sure to backup first. It’s a known bug that occurs when updating worlds.

Thank you that fixed it xD