UPDATE 1-19-2017: Another ham reached out to me about this, mentioning that it may be related to having extra spaces at the end of your callsign if it’s less than 6 characters. I loaded my programming in RT System’s FT-1D Programmer and went to Settings > Radio Menu Settings, then clicked the APRS tab. Here I was able to verify that an extra space does exist in the “My Callsign” field. I’ve decided not to test this further, but it should be trivial for someone to verify whether or not removing this extra space fixes this issue.
I have a Yaesu FT1D that supports APRS messaging. I set the callsign in my radio (via SET:12), and I set my APRS callsign as my callsign with SSID -7 via SET:9>23. (See the FT1D manual here or an explanation about APRS SSIDs here.)
I tried sending a message to CQSRVR and ANSRVR to test, but I never got any replies. I have a low-budget digipeater set up in another room using a laptop and another HT, so I checked the screen. The packets were received, gated, and responses were received and transmitted, but my radio never showed anything under messages.
I installed PocketPacket (iOS App Store) and using SSID -5 for it. I sent a message from my radio to my -5 SSID. It showed up on my iPhone. I replied to that message, addressed to SSID-7, it did not show up on my radio.
A bit frustrated, I sent a message to my callsign without SSID. It showed up on my radio. However, when I replied from my radio, the -7 SSID was appended, and so replies to the -7 SSID wouldn’t show up.
By changing my APRS SSID via SET:9>23 to my callsign only without SSID, I was able to get messaging working as expected.
So, in a nutshell:
Issue: APRS messages are not displayed on the radio when an SSID of non-zero is set via SET menu 9>23.
Steps to reproduce: Set an SSID to your callsign via the above-mentioned settings menu. Transmit an APRS message from another device to your callsign-with-SSID. It is not shown on the radio. Transmit an APRS message from another device to your callsign-without-SSID. It is shown on the radio.
Workaround: Set menu 9>23 to your callsign without SSID.
Expected behavior: When the SSID is set via menu 9>23, messages are shown as addressed to your callsign-with-SSID.
I will be emailing Yaesu regarding this issue and hopefully they can fix it in a firmware update.