What version decoder does your track use?
Isn't the 3 wire only compatible with AMB 4.5 and newer?
I think you might need to get the 2 wire Hybrid if your track is using an older system.
I am running
MRT transponders which work on all MyLaps systems up to AMB 4.4
I mount my transponder on top of the servo like this and the loop is buried under duct tape on the track, I have never missed a lap over the past 9+ years I've been racing with MRT transponders
