Yeah. There was an update that totally changed the scoring making it impossible to improve any scores obtained before the update and messed with the leaderboards as you say. I've been wanting to jump back in because all I really do on Horizon is drifting. It's made the game unplayable for me.
They added a drift club story recently with Mustang Mach-E 1400. I’m not a big drift guy but got three stars one every mission first try.