Realms unable to load

Speaking for a friend. We are admins on a Bedrock Realm, and the host has not been able to join on. Other members have been able to join with no issue. There is no problem with the host's internet connection as other games work fine, their security settings are working as they can join online servers such as The Hive or other multiplayer worlds. They have reset/restarted their router and nothing is different.They don't get any failure message as they cannot get past the building terrain screen, it is just stuck eternally loading until it eventually times out and says that the connection failed.  They have also signed in and out of their microsoft account, reloaded and there is still no change. Their current device is a laptop, but they have tried to log in on their Ipad on Pocket Edition, and the issue continues over there too. They do not want to be paying for something they can't access, and we are desperate to know a fix for this.

I've seen comments on youtube saying that copying the realm and replacing the old world with the new copy could possibly work, but we are worried about losing people's progress just for it to not work still. Please help and thanks.