Turning off 'All Motion' kills smart detection completely

[Kalsta]

There appears to be a pretty major bug with the Arlo app and/or the Arlo Secure subscription service (we're currently on the free trial). If I go into user Settings > [my plan] > Smart Detection > [my camera] and turn off 'All Motion' the camera picks up and reports NOTHING, even though 'People' and 'Vehicles' are still selected. I can dial the sensitivity up to 100%, drive and walk past the camera repeatedly and get zero notifications.

Clearly this is not how it is supposed to work, because when you turn 'All Motion' back on, an alert pops ups and says, 'Do you want to enable All Motion? The device will record all motion events. This will increase the amount of notifications and clips you receive.'