Long shot
Some of my Linux scripts are set to display end of line (eol) as a $ sign.
I don't think LX-200 protocol uses an (EOL) character
# sign is the EOL in LX-200 protocol
$ sign may be an invalid character in this protocol
$$$:V# That may be 3 <returns> and then :V# (as you said is an invalid command with no results returned)
What software sent that command.
Has it had a upgrade lately which sometimes resets your setup.
I don't see where a Time change would cause this problem either, But
As always I may be wrong again.
Jimmy