Hi McVitie,
I’m not overly familiar with RunwayHD (I did have a complimentary licensed copy for ‘support’ purposes but the licence expired some time back).
The general principle when starting a Nav App, however, is that you need to define the data source - with SkyDemon for example you select ‘Go Flying - Use PilotAware’. Prior to doing this, you need to connect the device running the Nav App to the PilotAware WiFi Hotspot so that it can obtain the data. This obviously requires the data source to be running when you start the Nav App.
So the sequence is....
Start PilotAware and wait ‘til the PilotAware WiFi Hotspot appears on your Tablet.
Connect your Tablet to the PilotAware WiFi Hotspot.
Start your Nav App and connect it to PilotAware.
Detailed instructions are available on the PilotAware website at...
https://pilotaware.com/runwayhd/Hope this helps
Best Regards
Peter