I have found a work around until a fix is created.
Solution found on Reddit:
Go to settings > data management > save data cloud > Minecraft And turn off automatic backup, then make a manual backup, After that, go to settings > data management > manage save data > delete save data and sign in in game
Basically, these steps back up your save data and dowloaded content to the cloud (you can get it back later anytime, don't worry) and then delete the save data so you have no worlds in your game. For some reason, this prevents the bug from happening and you can play on servers and realms all you want.
When you want your worlds back, go into system settings, save data management, pick minecraft and redownload your data from the cloud.
You have to do this every time you wanna switch from your worlds to servers. Save to cloud. Delete data. Sign in.
System settings, data management, redownloaded your stuff from the cloud.
Thread Link:
I am having the same issue! They have not responded to my submission either.
I am having the same issue. It's been 3 weeks and have been given no solution.
Why has no one reviewed this issue yet? I haven't been able to play on a realm that is being paid for for more than 3 weeks.
I have found a work around until a fix is created.
Solution found on Reddit:
Go to settings > data management > save data cloud > Minecraft And turn off automatic backup, then make a manual backup, After that, go to settings > data management > manage save data > delete save data and sign in in game
Basically, these steps back up your save data and dowloaded content to the cloud (you can get it back later anytime, don't worry) and then delete the save data so you have no worlds in your game. For some reason, this prevents the bug from happening and you can play on servers and realms all you want.
When you want your worlds back, go into system settings, save data management, pick minecraft and redownload your data from the cloud.
You have to do this every time you wanna switch from your worlds to servers. Save to cloud. Delete data. Sign in.
System settings, data management, redownloaded your stuff from the cloud.
Thread Link:
https://www.reddit.com/r/NintendoSwitch/comments/9yof26/minecraft_constantly_being_disconnected_from/