I know that people have had similar issues across devices but apparently there is no solution yet.
I've started using a vivomove Trend a couple of weeks ago. Several times now, it has mistaken a 30 minute meditation session for sleep and recorded somewhere between 10 and 15 minutes of sleep. The annoying thing is, of couse, that it replaces the correct sleep data of the previous night with these 10-15 increments of "sleep".
I can manually set the time back to the original sleep time in the app, get most of the original readings (deep sleep, REM etc) but the sleep score remains poor. This is what frustrates me the most, since this completely messes up the long term average sleep score which I'd really like to keep track of.
This didn't use to happen on my previous (now secondary) device, a Forerunner 35. It never recorded sleep during meditation sessions of any length.
The only solutions I can think of is taking off my vivomove during meditation sessions (possibly wearing the Forerunner 35), or recording a "fake activity" (such as yoga) to prevent it from recording sleep - both of which are lame and not always practical, i.e. on retreats.
Is any solution to this forthcoming? It would be greatly appreciated...