Matchmaking Failed, Error Code: -34601 (BF1 on Xbox 1)

Thanks for giving out some detailed info on that error, @FurzzyMrBear13

Another thing I recommend trying is clearing your MAC Address.

• From the Xbox dashboard select Settings>All Settings>Network>Network Settings>Advanced Settings>Alternate MAC address>Clear, then restart your Xbox.
• Check your Xbox Settings to make sure the clock for your Xbox is synced up with your actual timezone. 

I tend to see more errors occur during quick match and hardly ever see it at all when finding games with the server browser. If you run into this a lot I'd try going through the server browser to avoid it and perhaps try reinstalling the game when you don't plan to play it for an hour or two to see if that clears this up.

Good luck!