APRS.fi doesn't seem to ALWAYS send ACKs upon reciept.
I see the message on my phone, but on my TNC or LOG I don't see the ACK.
I have a re-designed version of APRSBOT, but with a Store & Forward component that needs to receive the ACK to show that a message in the Store has been received.
If I don't get it, it stays in the Store db and gets retried either on the next time the callsign-ssid is heard or every 6 hours until either a ACK is received or the number attempts is greater than "n" or the message times-out "x" is reached. "n" and "x" are configurable.
Is there a known issue?