Thanks for the reply. See below.
You issuded "sudo usermod ..", right?
After that, did you log off and on again?
Does command 'id' show 'dialout' as one of your groups now?
I’m not sure I had logged off and back on,
but I did just now.
Id shows that pi is a member of the dialout
What does command 'ls -ltr /dev/tty*' show when you have
the KUSB cable connected?
crw-rw---- 1 root dialout 188, 0 May 11 10:19
What exactly does not work? How did you test?
and it seems the only thing not working is the Test CAT
if the "Test CAT " button is not working then you should be
getting an error message window. What does that error message
window say, including the text revealed by the "Show Details ..."