Elite Drivo II recurring power drop-outs

[neil855]

I have recently had a recurrence of an issue that I had when I first purchased my Drivo II. I get recurring dropouts of power when training in erg mode. My computer running the training app continues to show my HRM and cadence (which is being recorded by the Drivo II) correctly, but power drops to zero and resistance goes. Usually I either have to stop, pause and start up again and it comes back, sometimes comes back a bit quicker, if I just pause pedalling or backpedal for a split-second. If I just keep pedalling, it does seem to come back but can take a longer time than I would like (up to about 15 secs, then I would always just stop/pause). I am using ANT+ for everything connected in to the computer/training app (TrainingPeaks Virtual).
The problem seems to be worst if I am doing a workout that involves short, sharp sprints - it almost always manages to cut out during these efforts - and seems less likely to happen over time when working on steadier/longer efforts.
I really don't know what to try to see if I can pin down the issue any further, but would appreciate any suggestions for the steps that I should take to try to isolate the problem.
I had another problem which might be related when I was doing another session that involved sprints - doing the session in erg mode, the power level didn't tail off after the sprint at all, so I relaxed at the end of the interval and then found I couldn't turn the pedals - so had to stop and allow the app to release erg mode so I could start again. Most recently, I did the same session without using erg mode and experienced multiple power dropouts.
Can anyone help?
Thanks!