On my main menu it says I have a day of playtime but in barracks its 15h. Anyone else have this issue or know a fix?
The Multiplayer Menu time likely includes every second spent after entering that area. That includes searching for lobbies and waiting to invite friends, along with private matches.
The Barracks is going to be a lot more accurate, along with the leaderboards.
The multiplayer time tracker records every second you spend after entering the multiplayer menu.
The Barracks will track time in actual games.