Huge frontfocus with Sigma 70-200 2.8

Hi guys!
I finally got my Sigma 70-200 2.8 APO EX (no hsm, no macro, no os) MK1 lens
I'm already suffering from a severe frontfocus problem, even in daylight!

If i zoom in to 200mm, the image will come out out of focus, but at 70mm its fine (except with some purple fringing)
What can i do?

AF Fine Adjustment doesn't solve this...i can solve, sometimes, for 200mm, but then 70mm is out of focus...

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14 years old suffering from LBA