SmartThings Multi Sensor won't stay connected and sticks on open until it discconects

My door sensor refuses to stay connected. I’ve tried it multiple times and it’s the same result each time.

I have the sensor connected to my back door. The larger part on the door and the smaller part on the frame. I connected it first time and so stuck it to the door. Everything seemed ok. however I few days later I noticed it was showing as unavailable. Since this is stuck a metal frame and door it was quite hard to remove, so I tried a reset. Even though the light was flashing green and red it refused to re-add. I tried this numerous times, removing the battery, holding the reset for ages, but nothing worked.

Today I got a Stanley knife and removed the door piece. I was able to scan the barcode using the new (rather than the classic) app. After a while of waiting for the connecting dialog to go, it can up as connected, So I stuck it back to the door. Within minutes it was showing as unavailable. I deleted it ad tried again. Exactly the same scenario. I’ve tried three times now and each time within minutes it goes to unavailable.

When I re-add it, each time it shows open (because I have it with me in the kitchen), but when I take it back to it’s pair on the door frame it stays showing open.

The door on which it sits is in my laundry. It’s about 5m in a straight line with no walls or obstructions to another Samsung motion sensor, which is directly opposite three GE smart switches which work perfectly (as does the motion sensor) There is also another motion sensor in the kitchen (approx. 3m from the door sensor just inside the wooden kitchen door.

How on earth do I get this working? It can’t be too far from a connection if the two Samsung sensors are repeaters as are the GE Switches. What am I doing wrong?

Does anyone have any insight on this? Why won’t it stay connected?

Metal doors tend to interfer with rf signals.
How far is it from your huh? Are the ge switches z wave or zigbee or wifi? Only zigbee will act as a repeater for the multi sensor (it is a zigbee device).

Thanks Tony, that sort of helps me a little I think. The door it’s on is a metal (aluminium) door. It’s approximately 8m diagonally below the hub. The hub is on the first floor and the sensor is on the ground floor. All the GE switches are z-wave. I hadn’t realised that the sensor was ZigBee. I think I’ve got rid of all our other ZigBee devices. We had a few ZigBee bulbs but my mother-in-law kept turning the switches off, so I replaced all the switches instead of the bulbs.

It sounds like I am best removing it and buying one that works on zwave with everything else.