Only first and last GTK3 Combo Box Entry Working

I use C switch based on a variable I set according to which GTK Combo Box Text entry is selected ( variable = 3 <===> case 3: ... etc. ). There are 4 entries. My trouble is getting the 2nd and 3rd entries to actually do something.

Only the first and last entries seem to carry the variable value properly.

I have tested it repeatedly, seeing if I need to use if/else rather than a switch, to no avail. It is probably more than a coincidence, though, that the middle two entries are ignored in the program. Right now, I am using 4 if/else statements. There is the same behaviour, however, with switch (only the first and last entries cause the program to do something, which, in my case, is cause a dialog box to show and then, upon clicking, launch a terminal window showing progress).

Please, please, help is much appreciated.

Thanks.

P.S. I am using GTK3.