Unity Mixed Reality App launches but is not connected to HMD
I just built an app for Windows Mixed Reality using Unity 2018.3 and deployed it using Visual Studio Community 2017. The build was successful and I managed to build my AppPackage APPX File (and install the certificate). However, when running this file, the app launches but is not displayed on the HMD. My HMD works just fine (I can launch apps from SteamVR) but there is no way to reach my Unity app from it.
Am I missing something?