This is a small bug that is slightly annoying to experience, especially if in survival mode, where when the warden is despawning/leaving/tunneling out and the player is far enough away from the warden(s(can affect multiple)) it will just stand there while the digging sound plays and then pop out of existance.

Why I say that this could be annoying in survival is because if I'm out of the range that the darkness effect affects, I want to see the warden leave. I have seen the bug happen multiple times on survival test worlds and they are all nerve-racking...

(Also I put this as 1.18.2 Pre-release 1 because for some reason the bug tracker only let's me have two options...)