Clicking a macro dropped the CAT for a few seconds, keyed nothing, then came
back.
ask() returned the first ';'-terminated frame it saw, whatever command it
belonged to. KY produces NO reply, so the next query — FA; from the poll loop —
collected a leftover frame, failed to parse it as a frequency, and ReadState
reported an error. The Manager reads that as "lost the rig": disconnect, wait,
reconnect. Hence the drop and the automatic recovery a few seconds later.
Replies are now matched to the command that asked for them: anything else is
discarded and logged, so a stray frame costs one log line instead of the link.
This also explains the silence — the send never got a clean run at the port
while the backend was being torn down under it.