I am not sure what exactly is the problem but worlds uploaded on 5.3 seem to have all their shaders broken so they are bright pink and not rendered correctly in both eyes.
Some worlds put you into a infinite reload loop showing you the world for a second before reloading it again.
The worlds seem to report 0B download size on the website as well as when downloading in the game client it says the total size is 0B while still downloading normally.
Oddly some of these worlds seem to have strange world ID and the two tested where the ones that kept causing you to reload
A list of worlds I tested where the following
Comedy Club by Vrchat
Forest Campsite by cubedparadox
Ted Stage by cubedparadox (This world puts you into a reload loop)
Windlands by cubedparadox (This world also puts you into a reload loop)