Hello... I have a few T300 APs, some of APs succeed joined to vSZ and some can't, Our customer used Google Application for provisioning APs. Has anyone ever experienced the same things ?
Do you mean the Android mobile app? What google application?
Any chance the APs have an expired certificate? Can you check the serial numbers of those T300? Especially the ones that didn't join? Is there any way you can set the controller using dns or DHCP?