Updated description from Avoma

The Bug:
Aquatic mobs (turtles, dolphins, axolotls, tadpoles, fish, etc...) attempt to pathfind through and get stuck inside non-full waterlogged blocks (fences, glass panes, iron bars, etc...).

Steps to Reproduce:
Enter a deep body of water.
Summon a hollow box of fences around yourself.
/fill ~5 ~-1 ~-5 ~-5 ~10 ~5 minecraft:mangrove_fence[waterlogged=true] hollow
Summon any aquatic mobs, for example, some turtles within the box.
Wait around a minute and observe the behavior of the aquatic mobs as they come in close proximity to the fences.
Take note as to whether or not aquatic mobs attempt to pathfind through and get stuck inside non-full waterlogged blocks.

Observed Behavior:
Aquatic mobs get stuck inside non-full waterlogged blocks.

Expected Behavior:
Aquatic mobs would not get stuck inside non-full waterlogged blocks.

Original Description:

When turtles are south of the fence, they will not choose other routes.

As shown in the video:

https://youtu.be/S32nHNqY6dY
Because the file is too big