Hi Christoph,
From my point of view it might be influence from next phase – if you use PMSM.
In case of BLDC, it should not be there. But, personally I could imagine case where it could be a result of some wrong implementation of amplifier feedback.
Could you please specify testing conditions?
Do you use our EVB or you measure it on your PCB?
Do you use our example code or you have your own application?
…
Have a great day,
RadekS