I like to pedal 100 or higher. I swear that Zwift was always trying to power break me down to 95 in erg mode. I have a saris H3 and I asked them, but the reply didn’t seem to understand my question so I don’t know if the way I felt was real.
I switched to trainer road this year, and erg mode works flawlessly. The h3 was known to be the best at erg modes de over tacx, wahoo, and elite. I don’t have much experience with any of those to know. With Trainer road I could achieve a cadence I wanted and not feel like the resistance would try to slow my cadence unless I fought it. With Zwift it always had to be a conscious effort to keep a high cadence.
That’s probably a different problem than yours but I’ve never heard anyone else say anything about this. If you drop your cadence into the 60’s (I’ve never had a slow down to 30-40), erg mode will apply the resistance for the lower speed of the freewheel. If you want to make that freewheel speed go faster again (higher cadence) there is going to be a lag as you pedal up and get hit with a lot of resistance until the trainer adjusts back to the speed change of the freewheel.
Trainers can perform differently at different speeds in their ability to provide a realistic feel. I thought that was my Zwift issue so I had more success in a lower gear (lower freewheel speed). However I switch to trainer road and it doesn’t make a difference in speeds below 25-28 mph. At least it struggles to provide resistance for my zone at a great speed that would go with a high demand for resistance. I have to think it’s a Zwift control thing for this reason that trainer road behaves differently.