What changed the last 2 months with the game?

I took a 2 months break from the game, couldn't resist the temptation and came back to it. Went from div 5 to div 3 without losing any games... I play a 4-1-4-1 for the longest time - shoutout to div10moments BTW.

And before that I was always a div 5, max div 4 casual player... What's going on?