I have a very weird problem we all know Fallout 4 is a single player game and about the only time it uses the internet is to sync save files, at least from my understanding. I play Fallout 4 about 4-8 hours a day depending on what's going on in my personal life, If I play for more than an hour I start to get latency that slowly progresses all the way up to 7000ms+. Fallout 4 happens to be the only game that causes this odd issue, even playing Elder Scrolls Online for a large period being 4-8 hours barely goes up to 200ms latency, and it doesn't even lag in game, heck I don't even notice it until I check my network settings on my Xbox. I do have slow internet though 1.12mb's download, yes slow, but I live in a rural area and this is about as fast as it can get unless you go satellite, but I'm not going to because of the issues with satellite internet in my area. I just plugged in an Ethernet cable I have as I was previously using Wireless, and I am not sure if it will work, but does anyone else have this issue or know how to fix it? My Xbox One is barely a year and 3 months old, I got it as a present from a friend on Christmas, December 2014. As a little note it's the Assassin's Creed Unity non-kinect bundle that also came with AC4 Black Flag that was selling for $349.99 at that time.

Maybe the best thing to do is check some of your auto save features and maybe disable them altogether.

Another option is to play the game in offline mode.

I am still looking for a method to disable the sync for game saves since I can not stand that feature in any game. The closest I have come to it is deleting most of the game saves and only keeping a couple.

Maybe you can backup the game saves to a usb stick and only keep a handful.

What's weird is that it's not syncing when it happens I play the game for let say an hour I go check my detailed network statistic and it says something like 800ms and as I continue to play it slowly increases, and when I went to bed yesterday it was at 7729ms. I couldn't even load the Xbox Store or even connect to Google on Microsoft Edge, and the Dashboard after a second or two pretty much turned blank except the parts that show up when you're offline like it was trying to keep connected and lost it. It's the oddest problem I have ever seen a computer based device do and I have dealt with a lot of weird stuff back when I played Xbox 360, PS3, PC gen games on PC like Skyrim and stuff.

I have a grand total of 49 games and Fallout 4 is the only one that does this weird and interesting problem.

Anyways I am going to try and see what happens with Ethernet plugged in, I'll report back if there is an improvement it may be several hours though to fully test.

Another thing you can do is a power cycle of the Xbox One by holding on the power button for about 10 seconds or so.