When I pair through Zwift, I use the Stages as my power and cadence source and set Tacx Smart as my smart trainer. When riding I am not getting any change in resistance from the Vortex. It has been calibrated correctly. Is there an issue with the Ant+ I am using?
Had similar problem - make sure tacx vortex isnt connected to any other devices via bluetooth or Zwift cannot control it. That was at least the problem with mine.
I found that calibrating using the iphone would prevent Zwift or TR connecting to the Trainer, until the iphone app was killed and the pairing re-made with the PC program.
Trainerroad has it’s own spin down calibration that solves this issue