Ok, what am I doing wrong / missing?

Played for quite a while, did missions, forgot which one was the last but I guess am still in the "intro" phase of the game.

If I save the game, the new save is titled "Tank Mayhem" even though I've finished all three Tank Mayhem missions (more than once.)

Also, aside from three repeatable DLC missions (the movie one, Genki, and the "superhero" one where you can throw fireballs etc) i get no new missions (and I've finished all the others I had), even when I get a notification in-game (driving, walking etc) about a new mission having become available.

What am I doing wrong, and how can I fix this?

Thanks in advance,