About The Iron trapdoor and Iron door automatically opened when Smooth Stone Slab placed on it

In 1.21.10 or above version,when the Smooth Stone Slab placed on the Iron Trapdoor,the slab will disappear and changed the trapdoor’s status(from close to open),seems like the slab somehow changed the door’s default value.

Not only this,in fact,the Iron door also performed like the trapdoor.And after those acts,the door and trapdoor would changed into a strange status,those could be opened by hands and redstone mechanisms were no need anymore.

Espeacially will appear in a server.