This issue is way more common than I previously thought.
Anyway I’ve made a lot of progress with this issue and have a thorough write-up of it here: [MORE NEW INFO] Client-Server Desync/Bad Character State
To those saying repair works - it doesn’t. This is some sort of server-side desync issue that’s manifesting in (mostly, but definitely not entirely) client-side bugs.
The fix for this issue is just to log out of the game and log back in. Note that this is different than exiting the game - if you exit prematurely, your character persists in the world for a short while and if you attempt to log back in before the character has despawned, the bug will still exist regardless of any client-side fixes you may have attempted in the interim.