If you try and leave the End to go back to your spawn point, it does not return the player to a respawn anchor, and it displays the "your respawn anchor may have been obstructed" message.

Steps to reproduce:
1. Set up a respawn anchor in the nether.
2. Set your spawn to it.
3. Enter the end (kill the dragon if needed).
4. Enter the exit portal.

This may be a duplicate but I did search for quite a while for this bug.