Why is my config app not discovering my device

I recently ported my application to NET+OS 7.4.2 and I’m in the process of porting it to 7.5.2, but I need the 7.4 version to work. My original application used 7.1 and it works fine except for a few ethernet freeze issues. My question is about ADDPRegisterVendorData. With my 7.4 version, my config app does not find my device. However, if I don’t register my vendor info it finds the device, but of course the firmware version, build number, etc does not display. Besides the Magic Cookie and GUID, is there something else required to get my device discovered. My registered vendor data includes the build date, version, built by, and device name. I don’t think it’s a firewall issue, because all of the devices built with 7.1 are discovered fine