Can't add range to Smartthings app

I’m trying to add my Samsung range model NX60A671SS to the Smartthings IOS app. I can see the range’s WiFi network on my phone ([range]E30A…). I’ve trained scanning the QR code or selecting Range in the app, the app says “Processing” for one second and then either nothing happens or it locks up. I’ve also tried “scanning nearby” and the app says no devices found. The range’s WiFi is on.

I’ve tried turning on AP mode on the range and it makes no difference.

Any ideas for how to get the app to find this range?