Novo Smart: Erratic cadence readings

[mknbl.56]

My novo smart trainer has been working fine, but the last couple of times I've used it the cadence readings are all over the place
one second they ore 60-70 then jump to 190 then down to 40 continually changing

power /speed readings are all OK and look to be about right

the same thing happens in zwift Elite my training and other apps so it seems to be a sensor issue rather than the receiving apps

how can I fix this

[jdbates93]

I'm having exactly the same issue.

Anybody else?