Missing Fuel Consumption Data?

While driving this evening, on a two lane rural road, I noticed for the second time in two days, that the fuel consumption data, that I usually have displayed while driving, was suddenly missing data at the 1 minute mark. I would expect to see this blank bar, if I was stopped for a light, or sitting in traffic, but my speed never dropped below 40 MPH during the entire 25 minute interval shown on the active graph. Does anyone have any idea why the data would be missing for that one minute span? I noticed the same missing data yesterday, when on a similar trip, again not stopping or going below 40 MPH. Today, I pulled out my phone and snapped a photo while driving. My 2013 Prius 2 is 11 months old with 18K miles on it.

 

Every morning on my commute to work, I descend from my house to work about 250'. Most of this drop is the last 2.5 miles to work. The car is in electric mode almost all of this distance, and it still registers the consumption at 100 MPG. I don't think that is it as it would still register the 100 MPG or some number other than nothing.

 

It definitely moves to the left as time passes. That was the second time I noticed it. The first time, I noticed it, I keep asking myself where I stopped. Then I realized there are only 2 traffic lights on that stretch of road, and even if I got behind a farm tractor, I would rarely come to a complete stop.