Sounds to me like it could be a power issue. Either the wheel's PSU or Windows 10 being more aggressive on power management. I've been struggling with some flight sim panels and a PC that's been upgraded from 7 to to Windows 10. Although people also take about not using USB 3 ports and hubs with my problems.
Yeh, it is apparently recommended to use USB 2 ports for the G29 which is what I am doing. Had another go at solving it this afternoon with some 'cures' posted on the net, but so far no luck. All other USB devices I have connected work fine & everything on the wheel & pedals works ok except the FFB, as I said it is quite stiff to turn & there are no FFB effects, kerbs etc, at all. Will fire up the old PC tomorrow just to make sure it is not something with the wheel itself causing the issue. It does seem it is quite a common issue with the G29 from postings on the net, but no one seems to have a guaranteed cure, just 'try this' & 'try that'.