If the Warden is summoned by a Sculk Shrieker and it spawns underwater, the Warden may appear for a bit before playing the unburrying animation. It may also play the digging animation, but be digging through the surface of the water instead of a solid block. This may need to be split into two reports.
1. Place water around a Sculk Shrieker, where the Warden can spawn
2. Activate the Shrieker and summon the Warden
3. Observe the Warden as it spawns in.