I have the Garmin 520+. I have both LiveTrack and incident detection enabled. LiveTrack went thru a several month period of being very unreliable after a Garmin Connect update in May 2019. Finally some half dozen updates later it seems to have settled down and mostly works.

I’ve had the incident detection go off maybe 8 times in 15 months, all false positives. Sometimes I don’t notice it and my wife gets a message. She’s leaned to check LiveTrack to see if I’m still moving.

I don’t know what sets it off sometimes, once it went off when I simply came to a stop at a traffic light. Smooth road, not a panic stop or other drama. Another time it went off in my driveway after I stopped the bike.

I did actually fall over once last year navigating a very tight switchback on a dirt trail in Whiting Ranch. I was barely moving and fell over, dislocating my left ring finger. The Garmin did NOT detect this one real incident.