Even simplified test would be to just restart drive in Granity, then not touch the wheel, and see if the Position Feedback value would be off by the 4-5 degrees amount.
I can say that I just did that at my end, without touching the wheel, and my wheel was off-center. Going to granity, still without moving the wheel, the position feedback value was -13700 which exactly corresponds to the amount my center was off.
So, this is a IONI firmware bug. Thanks for reporting! I will let @Tero know about this.
We have released IONI firmware 1.7.6 which fixes this issue.
It will be included and automatically updated in the next SimuCUBE firmware release, but you can manually update via Granity if this issue affects you.