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.
In 1.21 Realms bedrock, there is an issue where using the Nether Gate causes frequent server crashes and rollbacks.
I hope this gets fixed soon.