There is a bug in Mio’s Cyclo software which I have had a suspicion about for a while, but it became even more obvious after upgrading from the model 315 to a 405.
Both devices record tracks from when you turn them on (sometimes even before), and not from when you hit the record button. It’s obvious in mioshare, even Strava to some extent, and I have verified it with a GPX editor.
This is what a recording looks like in mioshare, even though I didn’t hit record until I was rolling down the main road. The GPS device was on for 10 minutes before starting, but it has recorded 47 minutes of nothing, then walking through the garden, and finally cycling.
This is what it looks like in my GPX editor. I have highlighted track 4, which a little while in contains the point where I actually hit record.
I have been speaking to Mio who has raised an RMA for me. They are saying no-one else has complained, so it is a fault with my device. We will see what happens.