[MC-264969] Horses can't be tamed in certain situations

Horses cannot be tamed in certain situations causing the player to just sit on the horse

Nothing happened. The player just sat on the horse and the horse stood still

Either you would be able to tame the horse like normal or the horse would throw you off

Linked issues

This is MC-185907, since water is a transparent block and, in the pillar case, part of the horse's hitbox is on an air block (also transparent).

Thanks for letting me know. I couldn't find that report 😛