Motion detected... FOREVER (Human Presence Sensor SNZB-06P)

Regardless of the sensitivity set, the device detects movement in the room and never switches off again, even though there are no people, animals, lights, LED indicators in the room…

To which zigbee gateway did you add the SNZB-06P human presence sensor?. Maybe you have a poor connection to the gateway? place the sensor close to the zigbee gateway. Check the sensor settings (after how long it should report absence). Set the value to 1 minute.
the presence sensor can also detect the presence of a person through the wall. stand behind the sensor at a distance greater than 4 meters and wait 2 minutes. the sensor should report no presence.

My Sonoff passive infrared motion sensors also do this occasionally. Oddly they seem to start working but I’ve no idea why. Repairing and changing battery seems to not work. On one sensor I’ve actually given up and moved it to a Home Assistant Zigbee2MQTT network and it’s worked straight away. Suggests to me it’s not the distal hardware but rather the coordinator of the network. What are you connecting it to? A Zigbee Bridge Pro?