Save time during package development and register the app instead of packaging and installing. You can do this with the PowerShell command:
This will register the app with the OS / Shell. You will be able to run the app from Start to ensure it runs properly. Once you have things working, you can then package the MSIX. (Use SDK version 10.0.17763.0+ of makeappx.exe to create the MSIX.)
Don't forget to test the packaged MSIX before deployment.