I had tingling as a result of arthritic/compressed disks in my neck. Eventually had a cervical fusion but still get some numbness, although not as bad. And my bike is custom & I've been riding over 20 years, so I guess it's just ... old age...(OK, there, I said it!).

If, after your fitting, you still have the same symptoms, I'd see a doctor & try to get referred to a PT who cycles. I was very lucky to get a PT who understood the positioning on a bike & gave me some excellent advice.

Let us know how you do!