Just a guess but I bet it has something to do with the swingweight or balance point of the shaft.
swingweight might be a bit too light causing it to feel a bit dead or firm.
or it could be that it’s a higher balance point shaft and that’s not something you’re used to? Or vice versa, you’re used to a counter balanced shaft and the ascent is not. I know nothing about the ascent to weigh in on the particulars of that shaft.