910 xt trouble recording swims

I've done 2 swim workouts with mine thus far.  In both cases, it recorded everything perfectly exactly as it should have except for once when I was testing to see what it would do if I did something different.

What you're supposed to do:
Press start
Swim your interval
Press lap when resting
Press lap when starting again
Swim your interval
Press stop

Every time I did it like that, the device worked flawlessly.  However, I also wanted to see what it would do if I didn't press lap.  It did record that I was resting in the middle of an interval but it got confused on the next lap counting it as 2 laps with 2 different types of strokes. 

I think by definition if you stop to rest you are no longer in that interval, so I have no problem pressing lap each time I start/stop.

I'm pressing start at the beginning, but when I get to the end of my interval and hit "lap", no distance is recorded unless I restart the watch.

hmmmm