Teleporting the player's mount causes rotation de-sync, previously did not

If a player's mount is rapidly teleported, the server will not acknowledge changes in the player's rotation. This only seems to happen on servers, like my Realm. My guess is that this issue pops up if the player's ping is high (>50ms). This didn't happen in previous versions.

This breaks maps that previously assumed that changes in the player's rotation would always be acknowledged while riding something.

What I expected to happen was...:

I would follow the position of a mounted teleporting minecart, but changes in my rotation would be still acknowledged. Reasoning: teleporting the player's mount does not move their rotation.

What actually happened was...:

My player followed the minecart, but changes in my rotation were ignored.

Reproduced here, with steps.

https://youtu.be/TyZ-NGnBxXs?si=Rj8ugRNPAd7r4P7Y

Rotation change is acknowledged on a local server, but not on my Realm.