I've been playing Minecraft Windows 10 for months and never had a problem with lag. Yesterday, I added two friends, played with them and then afterward played solo, still no lag. Then after I joined an Xbox Live Club, I could barely move and couldn't quit the game. I only have around 2 minutes when it runs smoothly before the lag returns. I tried multiple ways of reducing it, none worked. I don't want to quit Xbox live altogether! It could be a delayed reaction of playing with a friend or result of the club.