Launcher from Microsoft Store has some sort of bug, whenever I try it cannot connect to the Minecraft servers, at first i thought it was my WIFI, but the windows 7/8 launcher edition has no problems with logging me into my account. This problem started some time ago, but I kept using old Launcher (unfortunately the big disadvantage of this were problems with switching versions. I had to open another launcher just to play Minecraft: Windows 10 Ediotion)