This problem is affecting my current version of Minecraft while I play on my Realm.

How the problem occurs:
repro steps

I launch Minecraft normally through the Xbox App.

I click on my realm and it begins loading.

The game will load infinitely... 

I close the game, then in my Task Manager, Minecraft is still running under 'Background Processes.' 

I have to close the 'Minecraft' background process (that appears with the normal game icon), then restart Minecraft in order to load into my realm successfully!

I notice sometimes, the background application (or if I load into my realm on the first try), the 'second instance' of Minecraft application seems to be running and can cause lag spikes, frame drops, or something else!

(From my observation, the issue is only occurring with the Minecraft application)

There is an image below showing the normal Minecraft application running, and another image showing the background process that I close to successfully join my realm!