Not sure if this is a bug or not but, my average score has been 73.0 for quite a while now, despite playing several full rounds and a couple of tournaments.
Is it something I am doing wrong or is it an issue somewhere in game?
You have only played 3 ranked rounds in the last 2 months. A 73 today, a 76 yesterday and then you have to go back to the 27th of May for your last ranked round.
It wont change unless you play in ranked mode more often.