After the latest iOS 14 update apps now require permission to communicate with your local network. It is possible you may have declined this pop request by accident after the latest update installed on your device.
It will look something like this:
If you are experiencing difficulty with your iOS device seeing your network streamer after updating to iOS14 you will need to go to the iOS settings, scroll down to the StreamMagic app where you will see this:
You'll then need to select 'Allow Access To Local Network' and then restart the app. If this does not resolve the issue then you may have to delete and reinstall the StreamMagic app again, making sure that you click on the pop up when it appears to make sure you give permission for StreamMagic to find and connect to devices on your local network.