I run into the same problem when creating a mob grinder in 1.19. I was confused because my wither skeleton fall-damage-grinder works properly. My wither skeleton would fall, and it would only require one hit to kill it. This doesn't work on my drowned grinder. I will need 3 more hits to kill a drowned. If I increased the falling height by one more block, the drowned fall to its demise, no exception. I looked up to find wither skeleton and drowned both have 20 HP, so I started looking up on the Internet when I found this post.
I run into the same problem when creating a mob grinder in 1.19. I was confused because my wither skeleton fall-damage-grinder works properly. My wither skeleton would fall, and it would only require one hit to kill it. This doesn't work on my drowned grinder. I will need 3 more hits to kill a drowned. If I increased the falling height by one more block, the drowned fall to its demise, no exception. I looked up to find wither skeleton and drowned both have 20 HP, so I started looking up on the Internet when I found this post.