Go backwards on (Zwift) climbs w/ same W/kg?

Does the difficulty setting important if I use TR to control the trainer and record the ride? If so, what should I change it to?

During the race, I record the ride on resistant mode around 55% in TR. So I can respond the changes with one shift. However this doesn’t work as I get drop on the hills despite I’m around 4.5 wkg.

Onur