I'm assuming that when placing CVTG's you would zone them with the same zone number as the controlling Port zone but I'm not 100% sure!!!
Meaning:
Let say Field 15 is a port and Zoned as 4
You then placed a CVTG1 as field 32 and the controlling Port is going to be Field 15.
Is the CVTG ( Field 32 ) Zoned as 4 ?
Pokie