Official Forum

ERG mode looks much smoother.
Easy Start thing works as expected.
Zwift super tuck works as expected.
Cardio bridge works as expected.

(I'm using a Direto XR-T)

JetBlack and Zwift just released a firmware update to their trainers with "Race Mode" (10Hz signalling) over Bluetooth.

Another thing to check is if the Trainer Difficulty setting in Zwift is set to zero. That would effectively set the resistance to level mode and you wouldn't feel any changes in gradient.

Is it possible that you have another app connecting to your trainer? (e.g. My E-Training, or a Garmin/Wahoo head unit)

Agreed! Please fix!!!!

Agreed. This should be fixed. I've read several reviews that mention this and I know several people who bought other brands of trainers because of this one thing. And, as someone who does quite a few Zwift races, this is very annoying.

You will need to change the cassette. An 8 speed bike will not work with an 11 speed cassette. I think people have been able to get an 8 speed cassette to work on a Direto XR, but I don't think it's officially supported.

The power numbers reported take into account the offset value acquired during calibration. If the belt isn't slipping, you should be fine. I've ridden for a few years (with the original Direto) with my calibration number -4 from the number on the bottom of the trainer. Power values are within 2 - 5 ...