[Nickodemus_Maxwell]

It's not official yet, but I installed Windows 10 on Lumia 640XL DualSim using Windows Insider app.
Everything works fine. The photos and apps were all retained with all the data and logins, and onedrive works very well with Photos app.
But the contacts didn't show up. I thought maybe it's gonna take some time to sync them back from my microsoft account.
But after a day, they didn't show up. And as i noticed, there was no new email. Even though everything has been working great on my Windows10 PC.

So I opened People app, went to settings, added new microsoft account, filled in all the credentials (of the same account obviously), went through two-step verification and it was all done. Soon as i clicked on "Done" button, it went back to where it was before, as if no account was added at all.

Same thing happened with calendar app.

Then i opened outlook. It said "Set up your accounts first" So I did. I again added the same account over and over again. But soon as i'm "Done" doing that, it goes back to same screen saying "Set up your accounts"
It's like it doesn't recognize my microsoft account at all.

So I tried a different option. At the 'Add Account' screen, instead of choosing "Outlook/Hotmail account", i opted for "Exchange account". But there, as I filled in my username and password, it said, "This account is already added in your device".
So if its added why is it not syncing my contacts, calendars and emails?
And if its having problems with account, then how come my OneDrive works fine on the same device under same settings?

Please do help.