Harder resistance going downhill

Okay, I am going to bring this up again because its really making me NOT like Zwift anymore. I posted in someone elses topic about resistance not changing.

I just completed Ventoux and it did it on the way down 3times,for ex. going from -11% to -3% in a super tuck, then wanting to pedal after coming out of the super tuck to keep up speed, I could barely turn 50T and my 18T. I had to change it to 24T and even then I was putting out over 350w and only 55cadence. Once I pushed through it, all a sudden it was like a switch was turned and it was easier to pedal.

This happens on EVERY ride where I have to come down a hill and I am able to coast.