If your Reolink Argus 3 Ultra is not detecting motion as expected, working through the checks below will resolve the issue in most cases.

What This Problem Means

The Reolink Argus 3 Ultra uses a PIR sensor and AI detection to identify people, vehicles and animals. When motion is not detected, it is almost always a settings, sensitivity or positioning issue rather than a sensor fault.

Common Symptoms

• No motion alerts received despite people or vehicles approaching
• Motion events not being recorded
• Motion zones appear correctly set but alerts are still missed
• Detection works sometimes but misses events at other times

Safe Checks You Can Try

1. Check motion detection is enabled

Open the Reolink app, go to Device Settings and confirm Motion Detection is switched on. Also check that Alarm Push Notification is enabled so alerts reach your phone.

2. Adjust sensitivity and detection zones

In the Reolink app, go to Motion Settings and increase the sensitivity level. Tighten or expand your detection zones to cover the area you want monitored. The Reolink Argus 3 Ultra has a PIR detecting angle of 100° horizontal — ensure subjects move across this arc rather than directly towards the camera.

3. Check camera placement and angle

PIR sensors detect motion best when subjects move across the field of view rather than directly towards the camera. If subjects are walking straight towards the lens, consider angling the camera slightly to one side.

4. Check for interference

Nearby heat sources — heating vents, air conditioning units, direct sunlight on a surface — can cause false triggers or desensitise the PIR. Reposition the camera to avoid these if possible.

5. Check battery level

A low battery (charge via USB-C) can reduce motion detection performance. Charge or replace before testing.

When To Contact Support

If the issue persists after working through all the checks above, contact Reolink support for further help. Your device may be eligible for a replacement if it is within its two-year warranty.