Didn't Joshua just take a picture with Drake a few days ago? That is why he lost
It was indeed a Drake curse,
I haven't seen the fight yet, but here's my thoughts on the fight.
[1] Andy Ruiz Jr, was just a substitute fighter, so it might throw off Joshua a bit because he wasn't prepared for Andy.
[2] Joshua may have under estimated the "Mexican Butter Bean".
[3] Joshua wanted to impressed his American fans, over compensated and when he feel the power of Andy, the complexion of the game changes.
As far as I know there is a rematch close, so let's see if Joshua will opt for a immediate rematch or will have a tune up fight before facing Andy again.