126.96.36.199 Preview, 1.20.12 Hotfix
Steps to Reproduce:
①Create a new world, find a deep dark. You'll find some naturally generated shriekers. They can spawn wardens.
②Data-pick one. (Ctrl+Middle Button as Default)
③Check if it has been data-picked in your inventory, you can see the word "+DATA". (See attachments)
④Put it down and try if it can spawn wardens.
It can't spawn any warden.
Since it is data-picked, and displayed the word "+DATA", it should be able to spawn wardens.