So, I found this out because my computer clock was mismatched when I started playing MCC PC and I fixed it today. The problem is that after I did that MCC slowly just stopped working completely.
So, what I found out is that there is a file called ClockSkew.json in C:\Users\YourUserName\AppData\LocalLow\MCC which contains an integer value that is represents your timezone offset (or something like that). If that is wrong you just can’t connect online.
To fix it simply delete the file and it will be regenerated next time you start MCC.
This is a bug though, a bad bug that is not obvious at all, I spent 5 hours on and off trying to fix this doing everything google suggested, and everything I could think of.