The Band snap type strap that came with my Band has come off numerous times and I almost lost my Band. Couldn’t take it anymore, so I switched to the included regular watch type strap. That snap type strap shouldn’t even be part of the Band, it’s just too easy to come snag off.
I thought I would prefer the standard watch band type but I never installed it. I have been using the snap type that came on the band for a month and a half now, and I have had zero problems with it coming off or loose. I think I’m going to keep this one on at least until it breaks and I need to change it.
Don’t worry, the band will catch on something and then it will fall off your wrist without you even knowing it. Each time mine unhooked, I didn’t feel it but luckily I saw it slipping off my wrist and caught it. I’ll never trust that type of band again.