Of course channels have to be included in a scan list (or scan group, the same), which you seem to have correct. This assures that all these will be scanned when scan is engaged for that scan group.
But to be efficient and to start the correct scanning list, *each* of the channels in the said scan group, has to have what I call a « scan trigger » programmed *in its memory channel config*, which will trigger the correct scan group when the scan button is engaged while being idle on that channel. This has to be done directly *on the radio itself*, channel by channel, as the CPS software presently has bugs preventing doing it in the CPS (in fact, you can do it in the CPS but it serves nothing as of now, as it is not transferred to the radio when uploading the programming).
Oh and, if you want to keep things coherent, create zones that have the same names as the scan groups, and which include the same 16 channels.
This way, when you change zones, and if you change channels in that zone, you know that those will be scanned because your scan list will have the same name and the same members (with each member channel having the right « trigger »).
‘Hope this helps !