Can confirm. Minecraft Username: @RealRichNixon Brief Description: Spawners on MN (in the mining world, at least) are not resulting in mobs being spawned. Instructions: 1. Place a mob spawner of a type that is bugged. 2. Notice that the mob spawner is empty, and has nothing inside of it. Notice that mobs do not spawn as intended. How many times did you recreate this?: Several spawners have resulted in this kind of behavior. I've also tested clients Fabric 1.20.6 and vanilla 1.21.1. Result: Spawner "cages" are empty with the mob type not able to be discerned. Mob spawners do not do what they are intended to do -- spawn mobs. Expected Result: Mobs should be spawning, and ideally, the mob should be spinning around in the spawner "cage". Evidence: Catch me in-game if you need more information.
Thank you for reporting, we advise everyone to not use spawners or spawner crates until we have a fix for this. Added this to our top priority development todo list.
Spawners have been fixed. You may place & roll them once more. If you are missing something, please contact @ClarinetPhoenix and she will investigate and give it back to you.