I was using a compass to navigate my world with my base at world spawn, so I noticed this quickly. After using a nether portal to move a good 350 blocks away from my base I used the compass to find my way back to world spawn in the overworld but the compass took me to an entirely different location.

I found my way back and used the /setworldspawn command to replace the world spawn to roughly where it was but well away from any obstruction, on flat grass. Yet upon entering the nether it moved again this time to a different location. I repeated the process two more times and had the compass point to three different locations total.

I also noticed maps were affected. Freezing upon return to the overworld from the nether.