Using Flrig for both VarAc and Fldigi, both flmsg and flamp will both stop TXing shortly after a clean start. Immediately after closing VarAC, both programs transmit fine.
VarAC sends a PTT-OFF every 1 minute on the minute as a safety mechanism. Some Rigs has their PTT locked after a PTT-OFF command for some reason.
Does this what you experience ? happens on the minute (00 seconds) ?