I tried placing a bunch of carpets on top of each other and then I put a shrieker on top of one carpet ("can_summon" block state is set to "true" via debug stick)
What I expected to happen was...:
A warden would emerge after 3 shrieks
What actually happened was...:
The warden did not spawn, instead played the "warden takes notice angrily" sound after shrieking.
Steps to Reproduce:{*}{*}
Make sure the game rule "doWardenSpawning" is set to "true"
Put a tower of carpets down (like so in my screenshot)
Place a sculk shrieker
Use the debug stick to change the "can_summon" block state to "true"
Make the shrieker shriek 3 times, then step on the shrieker again
Listen for the "warden takes notice angrily" sound.
Where do you expect it to spawn? The shrieker isn't low enough to spawn the warden on the grass blocks.