Fixing is relatively trivial yes but this is not sorting by channel it is sorting by user defined order in TV setup (which is a bit too long to put in the sort options )I agree that there are bigger issues with Radio and there is plenty of reasons to be confused in My Radio. But I do agree with wolfi_b that the channels sort order should be as user configured it to be. Usually favorite channels are put on top. This should be possible. I am guessing this can be fixed trivially. We can make this tiny fix for next release, and do a rework of radio for 1.3.
I will look at this over the weekend or Monday but is just a case of looking up the current group then getting the group map then getting the channel ordering from the groupmap in the comparer.