CTS symptoms following fasciectomy / correct use of splint

I had a fasciectomy late September 17 for Dupuytrens contracture affecting my little finger. Immediate recovery was good and I attended the very helpful hand therapy clinic at K&C. I began experiencing tingling (like stinging from nettles), pain and numbness in my thumb and other fingers but not the operated finger. Worse at night. I described these symptoms to my therapist who thought they might be unrelated to surgery and could indicate CTS.
I read about CTS and completed the online questionnaire scoring 38%. Result may be lowered as one hand only affected. I recognised that some symptoms existed before surgery but far less frequent and intense. Barely troublesome. I went to see my GP who examined me and thought it very likely that I had CTS and advised the use of a wrist splint for 6 weeks at night and then review.
Firstly, I wonder what the relationship may be between the surgery I had and the development of these symptoms, if there is any precedent for this and if improvement can be expected without further intervention. I continue the hand exercises recommended at the hand therapy clinic. The splint at night reduces the symptoms and I sleep fairly well. Symptoms persist unchanged in the daytime.
Secondly, I wonder if I am wearing the splint correctly. It has a bar running the length of it which curves at about 30 degrees towards the palm. My therapist suggested straightening this curve a bit which I have done partially but maybe should do totally.
I am discharged from the hand therapy clinic as I had completed my allocated 6 sessions following surgery.

Any observations or recommendations most welcome.