The Alert cancelled message should correspond to motion that was created by BI that did not have humans in it. For example, lighting changes often trigger an alert which would be cancelled by Sentry smart alerts.I got an email back from Sentry saying they fixed my problem but left no clue what the issue was. Sure enough my next motion left this in the logs.
Sentry: Thanks for using Sentry smart alerts!!
It also has left this each time it was a false.
Sentry: Alert cancelled
The "Thanks for using Sentry..." are benign marketing messages to greet new customers.
-- Sam from Sentry