1v1 Ladder broken?

For the last seasons diamond 1 was around 4100-4400, diamond 2 3800-4100 and diamond 3 3500-3800.

How come I got placed in Diamond 2 with 4100 MMR, true MMR, no provisional games or anything.
Friends with 3600 got placed in Diamond 1 ?

I promoted at 4250 and I got in Diamond 1 which now is 4250-4600?

Not to mention I played vs Master league opponents that were playing like Diamond 2s… but had 4400 MMR.

Is 1v1 ladder bugged?

Team ladder is still the same.