Homegroups (if you mean the same as Windows means with the term) are no longer supported in Windows 10. So be prepared to live without a homegroup.

I doubt if it's related however. Turn all other computers in your homegroup off, and see what happens. If still the same, it's a setting or a program blocking that specific connection and not blocking any other connection.
If you can't find it, go back to factory conditions and it will work again.