So I play 100% mobile. Can a PC Player that is not a "Friend" invite me to a 3-hole or 9-hole Head-to-Head game, since that is what is happening.
Gashmaster1, I'm using the PC app, and I just tried to invite you from your Profile page (we are not friends), and there was no option to do that. So I don't know how you're getting those invites.
If you're getting unwanted invites from a player, you can always try blocking them.