SharingWithUNET Scene - No session started upon tapping the "Start" button

Same question as this forum post right here, but worded differently to avoid spamming.

I have the Available Sessions Interface in this sample scene in the SharingWithUNET folder as part of the Mixed Reality Toolkit; I can only use the HoloLens emulator at the moment. When I try to do an air tap on the Start button, for some reason a network session that's supposed to be created by the event listener for that button does not start.

On looking a script file (StartSessionButton.cs), I come across this statement where it must return true for a network session to start hosting.

networkDiscovery.running

networkDiscovery is of type NetworkDiscoveryWithAnchors. What do I need to do to make that flag be true? I loaded the sample scene as is, and I feel like something's missing in the setup, or I need to change configuration.