When you fly much it happens once in a while. Nothing to worry about.

I have completely lost connection multiple times when the aircraft is out of sight and the app on my phone crashed. The first couple times I got scared but then realized this drone is extremely intelligent and takes care of itself. It does not need the operator to watch over it every step of the way. The Spark literally takes care of itself. That's been my experience anyway!

a few time's my Spark lost video but i was able to still control it . next season i'm going to try to reset ( turn my phone off then on  ) only because my first flight always fly's near perfect .

I sometimes lose signal when there is any obstacle between Spark and me.

Just had to leave my drone in the water two weeks ago because of this.  What a waste of 500+ dollars! Serious feeling of loss.

Only 1 time and it started to RTH. It was about 3,000 feet away from home point. It only lost  Signal for about 5  seconds  or so. I have 100 flights so far.

I live in a non-FCC country and before learning to force FCC mode, I would lose signal almost everytime I went to fly. However, on each occasion, auto RTH initiated and brought the AC safely home.