The detector isn't listed as tested/compatible with the receiver, so that's something to consider. GE could have changed something with the data the unit sends....I say that because I've experienced issues with a GE device on an Elk that transmitted basic items like tamper and low battery but not an alarm condition. This was going back a ways in the firmware and when Elk supported the 548E and their unit.
But first and foremost, you need to try manually enrolling the device via tripping the tamper as listed on the receiver installation instructions.
Then you need to wait for the walk test function to time out. Want to say like 10-15 minutes off top of head. Then place it somewhere, such as inside a box, for at least 5-10 minutes without touching it. Then try testing it.