Have you tried the ZF suggested drive procedure after adaptations reset?

If you go to route of changing oil it's worth to change new solenoids and seals between mechatronics and gearbox. New ZF solenoids are 300€ for a set. I just did mine and it's not difficult. Still too early to say what kind of effects this has done. (Not had time to do the proper drive procedure and not enough miles.)

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E39 530dA -02 M-Sport Messing metallic
E53 X5 3.0dA -06 Sport Stratus grey
E70 X5 40d -12 M-Sport Space grey