I'm not an expert but I would try feeding it something like Bloombooster and see if that may trigger your vine into blooming. I had a wisteria that was really stubborn and I pruned it heavily and gave it plenty of bloom booster. It triggered blooms that next spring.

Good luck.

Named cultivars of Bignonia capreolata such as Tangerine Dream bloom here at California nurseries at 3 foot tall in one gallon cans. I've never grown seedling Bignonia capreolata, but ones I've seen here don't compare to this cultivar, which where I've used it blooms from March into late May, and scattered repeat bloom in summer. Worth looking for. Otherwise, bloom fertilizer with no nitrogen is generally good advice, but perhaps too much shade is the culprit, also.

Attaching the pic of my vine. North facing, but gets plenty of sun throughout the day. This is a 10' high pergola, so you can see it's doing fine aside from not blooming. Aside from the grape on the post next to it, and honeysuckle two posts down, it's put on the most out of all the vines.