Can't connect to specific 8 year worlds as owner; recent update caused it.

Opening the worlds leads to "Unable to connect to the world. Please check your connection to the internet and try again." I am the owner, I turned multiplayer on or off, and it is not a Realm. All other old worlds work fine, and copies of these two worlds do not work either. I disabled my Xbox connection to the internet and it has the same effect. Again, I am the owner and it is saved to my console. No connection should be failing because a connection in not needed for offline and hosted worlds.

When it reaches the "Unable to Connect" screen, my internet slows tremendously. Barely any device can load webpages, reddit, or anything using internet. It appears that screen hangs and causes the internet to slow, even after selecting "Ok" it takes up to 1 minute to return to the main menu. Without much knowledge of this type, this appears to be some kind of memory/connection leak based on the long pause and slow internet. 

Uninstall and reinstall did not fix this issue.