Variation in power output

I’ve been Zwifting for a couple of days now, and I’m using a TacX Neo.

I’ve participated in a couple of group rides where you have to maintain your power output for different sections. I’m finding it really difficult to maintain power levels.

It seems to be that for a given effort the wattage fluctuates up and down anywhere from +/- 20 Watts up to maybe +/-70 Watts. For no discernable change in my input power (I can’t feel any difference in my legs with resistance or cadence).

This is causing me to “fail” race sections, as I’m not maintaining the correct power. For example I have to sprint to 325W for 30s, I push hard and suddenly I’m getting told to reduce power, so I reduce power but it’s mega low now, and I can’t consistently get the power to stick to 325 so I end up failing.

Is this a common issue? Looks like the Tacx Neo doesn’t need calibration so I’m not sure what to make of this?

Are these group workouts you’re doing? If so are you in ERG mode?

What happens when you do a regular workout? And if you are doing a workout in ERG mode you aren’t changing gears are you, you don’t usually change gear in ERG mode.

I’m having the same issue with a Tacx Neo on (indiviual) structured workouts. Been following a training plan flawlessly for a couple months. Power would change and hold at correct value within a watt or two.

Beginning Friday the watt levels started fluctuating like you describe. Today erg mode isn’t working at all. I need to shift gears to manually change power levels during a workout. Makes training plans pretty much useless.

Stopped working Friday on IOS (iPad). Stopped working today on Apple TV.