Game Breaking: Opening Minecraft Bedrock Edition on Xbox One console forces Xbox Live account sign out

I sign into my Xbox Live account right after powering on my Xbox One console, then open Minecraft Bedrock Edition. During the initial loading sequence, the message "Bye (My Name)" pops up, indicating my sign out from Xbox Live. I allow Minecraft to finish loading so that I can use the "(Y) Change User" feature from the main menu, but while the Minecraft application is open I am unable to sign in to my Xbox Live account and therefore access any of my worlds, skins, maps, texture packs, etc. I close Minecraft and attempt sign in, which works perfectly. Opening minecraft again forces sign out again. Troubleshooting steps so far have been: power cycle the console, change password to Microsoft account in case I am being signed out because someone else is playing Minecraft with my account without my permission (sneaky younger brother), and check for updates to console firmware, Minecraft, Microsoft store, and anything else that might be related. Occasionally instead of signing me out of Xbox Live it gets stuck loading indefinitely whenever I launch the game.
Quick Update: I managed to open Minecraft and make it to the main menu without being signed out, so I selected play, and navigated to "Sync my worlds and data" because my worlds were all missing, and I wanted to play on a specific world. Clicking this instantly crashed the game, and reopening it put it back in an indefinite loading state again.