Kickr v5 worked great for 4 years, zwift, dircon, win 10/11... two days ago suddenly not responding to gradient changes, no resistance within zwift. I end up spinning at high cadence regardless of actual gearing. Bounced kickr power, updated firmware to no effect. Using the wahoo fitness app and connecting via BT, i can get resistance using erg mode (i think their app calls it "power" mode), but when I try "sim" mode where you can manually dial in a gradient change i get no resistance. I have a support ticket open with wahoo, so far they just asked me to ensure blue pairing light is solid and that I have updated firmware...
So I am thinking that erg mode and "sim" or responding to gradient changes modes have to be separate circuits? I was thinking it had to be a software issue but the test using wahoo fitness app above seems to indicate otherwise.