Weight Weenies

Hi! I have since a few years a zipp super 9 disc wheel and it has developed a creaking sound. The wheel is not used much and all the grease is the same color as new inside the hub.
I still took it apart and cleaned and regreased it all. I tried a different skewer, and on another bike with the same issue. From what i can see all the small parts don't show any sign of rubbing on one another. The bearings are also in that same condition but the bigger bearing seems a little unsmooth when turning back and forth with the finger.
I guess next step would be to replace the bearings but i don't think that would be the issue. I will try to get some new bearings on Monday.
Any thoughts or suggestions are welcome.
https://www.youtube.com/watch?v=Ba78ovfFAM0
Regards Victor

New genuine bearings were installed and still the same problem. Maybe just slightly less creaks.
I read somewhere about someone with the same problem and it was the hub coming loose from the rest of the wheel. Maybe thats it, i don't think i have any receipt but maybe i could still try to claim warranty? Says lifetime on sram/zipp website.

Edit: Higher tension on the qr seems to make it worse.

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