I temporarily turned off my 5Ghz wifi while I setup my Pro575 ... once it had the connection then I could turn everything back on
You said you couldn't "get the app to connect to wifi" but I'm wondering if you mean the grill since the app uses your phones connection to the local wifi network. And actually the grill uses the local wifi to connect to the cloud which then the app connects to, there isn't a direct connection from your phone to the grill (that's why we can fire up the grill from the office before we head home to through the meat on)
Sorry if I'm over-explaining.