Can not pair new door sensor anymore with Samsung ADT hub

I bought a few more door sensors but every time I tried to add them with Samsung App on my iphone, it always stuck at the pairing stage after QRcode scan (hub will go into inactive mode for like 4 minutes then back to ready to arm status). I tried manual mode too and it does not work either.

Anyone had similar frustrating experience before? Thanks.

is anyone able to help from support?
I am having the exact same issue as the person above.

I have the same issue here, new ADT door sensor does not pair, I got it without battery, I plug the battery before scan itas code, is that the issue?. Any ideas ? Do I have reset the ADT hub ?

Sorry Im really late, I solved it a couple months ago:

  1. At the beginning I tried pair door sensor close to the destination door without success (ADT/ST hub is upstairs, less than 10 mts point to point), many attemps. By luck, I took door sensor to TV room really close to ADT/ST hub (2 mts); then voila ! It paires !.

  2. When I installed the door sensor in the door then the signal was always opened, no “beep” at all in the hub when I opened the door: Then I found out that wider part of the sensor has a little arrow to mark the correct side to be next to the magnet, so then I turn around the wider part and then works !.. Its working until now perfectly.