The only thing I noticed, is the "Scan Off-Hook" box is unchecked as depicted in your "Scan Information" menu. I set my TK-880 up as your radio is programmed, with the exception of the Scan off-hook. At first I thought you may have a feature conflict as you have two features with the "Scan" feature selected and that is not the case. Also, I unselected the "Add Scan" box in the Group Edit menu and that was not the case. I was able to enable Scan and have the icon on the display.
I am unable to duplicate your particular problem. Some times the TK-880 key assignment buttons go lame. Maybe your "SCN" Key Button is defective. Take the Scan feature off the foot switch feature and assign it to one of the ABCD buttons and see if that is the case.
Also, you may be aware, but you can not legally transmit on channels 8-14 from any Part 90 LMR radio unless you can get the transmitter power down below a half of a watt ERP, which more than likely you won't be able to do that with a mobile. Maybe a Part 90 LMR portable may be possible, but not a mobile, unless you used an in-line attenuator.