Only recording from coffee shop to home not the entire ride??

I have the RTL515, and I stop halfway for a coffee. Now all of a sudden when I check the footage it has only recorded from the coffee shop to home, not the entire ride. I tried again today and ensured it stayed on, even the light, whilst at the coffee shop and it still only had footage from the coffee shop to home. Any suggenstions? I have the garmin edge 840 so it is also a current model.