Bug UI render sorting broken in 2021.3

I have a few UI elements layered on top of each other in my game and those UI elements get enabled and disabled when they are or aren't needed. This has all worked perfectly fine since the 2019 versions of Unity up to version 2021.2.17. I just updated to 2021.3 and noticed that some UI elements weren't working correctly. Through testing, I've discovered that the sorting breaks when an enabled UI element is disabled and then enabled again.

Is this a known bug that will get fixed or is all development now focused on the new UI toolkit? I can't sort the issue tracker by date added and searching for this specific issue isn't very easy to do. Does anyone happen to know what's causing this and if there are any workarounds?

Until it gets fixed I'm stuck in 2021.2.