Got a Direto this month. Essentially random whether resistance changes or not on a ride. A couple of rides it worked, but for most rides it didn’t. I always make sure to connect via Fe-C. Plus there’s a heck of a lag.
ERG mode is very wishy-washy - simply never reaches the target but floats 5-10% below unless I spin up to 110 rpm, then it will fall back down if I go back to 90 rpm. I generally ride in the 85-95 rpm range and typical gearing is 52-19.
I’ve tested ERG mode on golden cheetah and Rouvy and it doesn’t have this problem. Something in Zwift is causing it.
I’ve ridden ZWIFT extensively with a Magnus and it didn’t have these problems.
btw, using ANT+ with Windows 10. Always select FE-C. Usually take power from powertap chainring output but sometimes ride with Direto power output.