@Alexg612 

As a battery-powered doorbell, TD21 stays in sleep mode most of the time to conserve battery. When the PIR sensor detects movement, it will wake up the doorbell, then the doorbell will start detection and recording. PIR sensors work by detecting changes in thermal radiation in their environment. In your current setup, it seems like the doorbell is aimed at monitoring a parking space, where vehicles typically reverse into the view from a distance (radial motion), correct?. This type of movement produces a relatively weak thermal shift, which may not be strong enough to reliably trigger the sensor, leading to delayed or missed wake‑ups. In contrast, lateral motion, such as moving across the field of view from left to right, creates a more distinct thermal gradient, allowing the doorbell to wake promptly and begin recording. When you open the live view in the app, you wake the doorbell up manually, so it starts detecting and recording right away.

Check out this article to learn more about how it works and how you can get the best detection from your device. How to Install and Configure Battery-Powered Cameras for Optimal Detection Performance