Hello,
Unexpected
The sniffer with its head above water shouldn't drown.
Steps
Build something like this:
Summon a Sniffer (exemple: in this case, i used "summon minecraft:sniffer ~ ~-4 ~" on a command block.)
Video
MC-261203
The Sniffer Drowns While He Has His Head Above Water
Resolved
Works As Intended
1
Drowning isn't based on head position, it is based on eye height of the whole hitbox being in water. The head isn't in the hitbox.
There's no bug here.