Adjust Nuvinci nfinity gears
So you are saying that the range of ratios available seems to have changed after servicing, so the lowest ratio available is higher than you want it it be?

I think you may be on the right track with the cable adjustment. The cable may be mis-adjusted so the hub is not at it's lowest ratio when the twist grip is at it's low limit position.

Loosening one cable tensioner and tightening the other should shift the relative position of the twist grip and hub mechanism. Keep track of how many turns you apply so you can get back to where you were if you find you are adjusting it the wrong way.

Link to service manual for the hub: https://www.gazelle.nl/media/gene-cms/h/a/handleiding_nuvinci_nfinity_1.pdf