On my (Bedrock Edition) Realm, whenever I or anyone else enters the nether, it takes a while to load, lags for a while, and then can lead to a crash. A crash happens often if you open your inventory, or a chest, or if you go back through the portal(you will make it through, then a 10 seconds to a minute later it will crash and when you reload you'll be back in the nether), and then at random if you hang around for too long. These problems do disappear for the most part when I travel further into the nether(so I'd think something to do with those initially loading chunks). I've also tried downloading the world and trying the world locally on a device, but it didn't even successfully load the nether each time I tried.
The End works fine, and as far as I can tell other portals(far away) are fine, but going back through the main central(crashy) portal once successfully in the nether still causes a crash, and entering the bad portal and leaving through a portal far away will do the same.
This bug has been going on for a while, since the update that added the ability to choose which server you could connect to for realms was rolled out.
The same situation has been occurring in my Realms survival world since version 1.21.93.
Using this Nether Gate causes extreme lag and crashes, which often result in rollbacks of around 40 minutes.
I hope this problem is resolved as soon as possible.