Hostile mobs with their heads in transparent blocks are not attacking the player

In version 17w49b the behavior of hostile mobs has been changed, so that when their heads are in transparent blocks they can see and attack the player. This has been classified as "Works As Intended", as you can see in the bug report MC-122988

But since Minecraft 1.13-pre7, hostile mobs with their heads in transparent blocks can not see or attack players. Probably caused by the bug fix MC-124126