Want to verify this is still a problem and add some information.
In my case I was attempting to add a new texture pack I had created to my realm. The copy made of the realm is 165.8 MB large. when attempting to replace the realm with the copy it gets stuck on the uploading world screen claiming 164.1 of 164.1 MB are complete. Leaving the only option to cancel.
I have waited over half an hour for it to move past this screen on multiple occasions with no results.
At first I thought it was a different issue with texture packs as reported in ticket REALMS-1347 as the first few times I was able to re-enter the realm, and it looked undamaged except my new pack was not uploaded, and the previous one applied was gone. However I followed the steps on that ticket, resetting the realm before attempting to replace it again, and now the world my friends and I have created in that realm is no longer available on the realm itself.
Could not find more recent non-duplicate version of bug report.
Can confirm bug is still active in Bedrock edition, and can happen in Realms. Recently entered a portal at -320, 70, -2 The corresponding exit in the nether is at -40, 70, 0. However I found myself somewhere around -300, 45, 0. I was on an island surrounded by lava, not suffocating in a wall. I do not know exact location as I was surprised and walked around a bit before taking notes, I was eating some food while waiting for portal to activate.
After dying I reentered portal and ended up at correct location, so did confirm exit still existed and was also not able to reproduce.