After I upgraded my pc to Windows10, i realized that the soulmate heart icon was lost in my friendlist, but instead of it there is a square icon now. LOL
I wonder if the game's some features are not compatible with Win10 or not.

I'm not sure if it's the features in the game, I think it's Windows10.
Correct me if I'm wrong though.

It's an issue with Windows 10 and standalone. Known bug.