I have four Kenwood TK-805D radios that I am having an issue with programming. I saw there were some changes with the front panel programming after 4120000 serial number, but did not know if that affected the scan feature when programming the radios with the KPG-6D software. Programmed four radios the same with the software. The older ones (below the 4120000 serial number) will not scan when the scan button is pressed. The newer ones (above 41200000) will scan once the scan button is pressed. Any ideas why the older ones won’t go into scan mode?