Cadence error with tacx vortex smart

Hi guys,

I am using my Tacx Vortex smart for 9 months with zwift and lately, the Cadence is’nt right anymore. It’s pretty stable at the beginning of a session and then goes from 1 to 150 uncontrolably. Sometimes it stays between 10 and 60 even if i pedal around 100… This is really annoying…

I’ve tried the Tacx calibration but the zwift one did not work and the zwift app was not able to calibrate my trainer…

Can someone help me here ?

I’m using macOS Catalina and the latest version of Zwift.