Odd Mission Control Dialogue Box

[jbblunck]

I use Mission Control on an iPhone with a Creo SL. My Mission Control also ports to Strava. All fine and dandy until I paired a new Polar OH1+ heart rate monitor. I'm getting an odd dialogue box that pops up repeatedly and randomly during my ride. Mission Control is the only app active. The heart rate reporting is active and correct, as are all the other stats.

Have any of you seen this?