The latest beta of Unifi Protect includes the start of Ubiquiti's version of AI, and introduces a concept called Smart Detect, which currently can identify People on specific Camera models. When this is enabled on a Camera, the event type changes from a motion event to a smartdetect event, and as such these cameras will no longer trigger motion events.
This release is a quick fix for the people who have upgraded to the latest Unifi Protect Beta version. I will later introduce more Integration features based on these new Unifi Protect features.