the vids are over 10 megabytes sorry...
Also if a block is placed where the portal should be, the block will be deleted if a player goes through the Overworld portal.
EDIT: I am not able to reproduce the bug explained in this comment.
I was in legitimate survival (no cheats) I had just entered the end dimension after setting my respawn point next to the portal. I entered the end dimension to fight the dragon but was killed by the dragon's breath bug (MCPE-40344). I immediately respawned to collect my inventory however, there were no levels of experience where my items were.
am still having this issue. i copied my world recently to do some testring, and when i returned to my original world, no raid captains have spawned. i have set up a farm, and have been afk for 5-6 hours, yet still no spawns.
My issue is on the Xbox platform
I seem to of found this issue is already reported. Please ignore this post.
Bukkit/Spigot/Spout or Vanilla?
I have not experienced this personally, I saw it in a YouTube video on a vanilla 1.15.2 server.