Summary:-

Mobs see dead coral fans as a full block, it's just like the button behavior, but it has made it's way to the dead coral fan. 

How To Reproduce:-

1:- Make a 3 blocks bridge above the ground.

2:- Break the center block and replace with a dead coral fan. 

3:- Spawn a zombie in the left or right & spawn a villager in right or left

Observed results:-

The zombie pathfinds it's way through the dead coral fan.

Expected Results:-

Mobs should not see dead coral fans as full blocks.