Did you install the game on the HDD instead of SSD like suggested earlier?
Another feature I've noticed do funny things is the background activity of the Store Apps. Go to the Store, click the ... icon and check for updates. After having done that, uninstall every app you don't use. Some of them can be uninstalled through
Programs and Features, some can't be found there. For those, scroll down the Start menu and right click the ones you want to get rid of.
Then there's the suggested apps, which only have a tile in the Start menu. Right click>More>Turn Live Tile Off (or
turn them all off at once), then remove/unpin those you don't want. Turning off applies to those you have to save as well. There's no need for the Store tile to show online ads while you're playing!
Also, there's a bunch of settings you'd possibly want to scroll through and disable most of them. It's tedious, I know, but there's no other way than opening each Setting menu one by one including the sub menus and trying to figure out whether you want/need something or not. Occasional suggestions are on my "not needed" list as well as various hints and tips based on my behaviour. Not to mention allowing apps to use my camera, microphone, whatnot! Just make sure you don't accidentally disable your AH voice!
Make notes what you do so you can easily find a setting you'd like to reset back on in case some needed feature stops working. Happy hunting!
Oh, and I didn't find if you've ever mentioned the make and model of your power supply. That's another potential culprit.