Describe the bug
Advancements are lost between changing dimension or rejoining servers & worlds

To Reproduce
Steps to reproduce the behavior:

1. Mark a(n) advancement(s) for it to show up in the advancement tracker
2. Change dimension (nether, end, or other) OR leave Server or world and join it again
3. Advancements tracked are gone

Expected behavior
Advancements tracked should remain, as marking them each time is just annoying and lessens the use of a "Tracker", since now you have to remember about the advancements instead of being reminded by the tracker.

Thanks for the report. I currently working on implementing this to allow to store the tracked advancements per Server.