I have successfully installed the Linear relay on my garage door. I integrated it into my SmartThings hub. It works 75% of the time and the other 25% of the time it doesnt work. When it doesnt work, my physical garage door switch mounted in my garage stops working. Needless to say my Wife is getting frustrated.
(1) Double check that the wires from the Linear actually connect to the switch and/or don’t short circuit. (For me, the wires from the Linear were much thicker than the openings for the switch, so I had to cut them smaller). If that’s not it, (2) contact support to see what the signal strength for the Linear relay is. I installed a z-wave light switch between hub and the Linear for it to work.
Yes, most zwave devices that are connected to power (not battery) act as repeaters. The signal strength way vary based on other over the air network traffic around your home. The guys from Smartthings support were able to check the device remotely though and should be able to tell you if there is a potential issue.
How are the relay and wall switch wired to the opener? I have never had an issue like you describe. I have my relay inside a double gang box in the ceiling along with the receptical supplying power to the opener. The wire from the wall switch also comes down out of the ceiling in the same spot so I twisted each wire to a relay wire and then I used a piece of telephone wire and twisted those to each relay wire as well. So basically 3 wires twisted together for each wire. The other end of the telephone wires goes into the opener.
Note that the when the light is on on the relay it is ready to receive input. If the light is off then it is in the equivalent of holding the button down. To lift the door and then stop the door you would want to hit the physical relay button 4 times. 2 times to get the door moving and get it back to ready state, then 2 more to stop it and get it back to ready state.Once you have it working reliably from the physical switch make sure you set the device type in the IDE for Z-Wave Virtual Momentary Contact Switch. The programming adds in the second tap to get it back to ready state.
My guess is that the relay is on the edge of connectivity and that if you have my above suggestion configured then it is not receiving the reset. I was having this problem and sovled it by installing a repeater closer to the garage. I was well within official range but this fixed it for me. You could also try rebuilding the virtual zwave network.