I would share that piece of data with Garmin, as it is good troubleshooting data. The loss of the Number implies a short coming with the transmission. The other sysytem kept presenting with the limited data, but garmin did not. This implies some poor error handling code that used an all or nothing approach when deciding to call the input failed and error out the routine.A friend of mine was flying next to me. He was only running a transponder. When the traffic would disappear his plane would still show up but no tail number or anything. Just the diamond.