It has been my experience that the number of channels displayed will stay to the max for the radio if you do the following:

1 Download from the radio

2 Change displayed channels to “Show Empty” (optional)

3 Set number of channels to max number for the radio

4 Save the configuration to .img file

Now whenever I open that .img file it always displays them all.

Note this is on a Windows (10) machine.

I currently run CHiRP version daily-20151020.

Hope that solves it!

Bill

Callsign: KW9WR