Nintendo Switch Minecraft vs PC Halo: The Master Chief Collection: Fatal Error

I am going to keep this as summarized as I can, but there is a LOT to this, so buckle in.

A little over a week ago, my version of Halo: The Master Chief Collection started crashing with the error: Fatal Error. I first thought this was a graphic drivers/card issue, but after updating everything, it still happened. But only sometimes. Weird, right? Well, through trial and error, I found the source of this crazy issue, and it makes absolutely no sense to me:

When Minecraft is booted up on my Nintendo Switch, it crashes Halo: The Master Chief Collection on my PC. So, I did some digging. A lot of articles give fixes like 'delete this credential in credentials manager' or 'run these commands on the CMD prompt as administrator'. I'm here to tell you, I've done it all, and nothing works. I've spent multiple, multiple hours in support with Microsoft, Nintendo, Halo Waypoint, and anyone that is willing to offer their two cents. I've initialized the switch, created a new Gmail, new Microsoft account, re-purchased Minecraft, and STILL it crashes my game. I've created a new Microsoft account with a new gamertag, signed into Halo: MCC on the new account, opened Minecraft on the completely new account, and even now, it still crashes.

Another detail I've noticed is that it works if the two devices are on separate internet connections. My computer is connected via ethernet while the Switch is on the wifi, but if I put the switch on a mobile hotspot, there is no issue. Somehow, these devices are communicating over the network and sabotaging my game.

I've come to realize that I just cannot play Halo: The Master Chief Collection at the same time that my son plays Minecraft on his switch. No matter the accounts used on either device, no matter how many times I initialize the switch or reinstall Halo, there is just something deep seeded into my computer/his switch that holds on to the connection they had.

I've come to the conclusion that the only way I personally could fix this issue is by fresh-installing windows and signing in with a new Microsoft account, but I do not want to do that for obvious reasons. All my preferences, achievements, games, everything will be gone, just so I can play this one game.

This is the final boss of tech problems. Multiple supports from the three leading game companies in the world have come up short with solutions. I am open to any and all suggestions, but just trust if you google the issue and see a solution on a forum, I've tried it, and it hasn't worked.

Edit: One more thing I wanted to add is the Nintendo support agent I have most recently talked to was able to easily recreate this issue by linking his Microsoft account to his Minecraft on his switch and booting up The Master Chief Collection. He immediately got the same fatal error, so I know it's not simply my account, but any account with this setup.

:)