I have Raspberry Pi 3 with Windows IoT installed. It's connected to wired network. I want to use its SoftAP functionality as described here: https://docs.microsoft.com/en-us/windows/iot-core/manage-your-device/DevicePortal#iot-onboarding to use it as Wi-Fi access point for my phone. I am not connected to any Wi-Fi network on the Pi and there are no profiles created. I get the "Internet Connection Sharing started" message on Windows Device Portal and I can see configuration change on connected display. Still, I can see no new Wi-Fi network on my phone and my Pi can still see other Wi-Fi networks (I don't know if it should or not).
The WiFi works after I use IoT Dashboard and select "Open network share" option from right-click menu. Its SSID is different from the SSID I've chosen in Device Portal ("AJ_[original SSID]_[some random string of numbers]") but it works otherwise.