Stop NS w/BU from blocking modern UI Apps

Norton Security keeps blocking the Plex Modern UI app in Windows 8.1. It's a known good app, but I keep getting the pop-up that says it's being blocked and the app loses Internet Access. Since it's a Modern UI app, I have no idea how to unblock this app in Norton.

I find this disturbing because Norton tells me it's blocking the app, but it does not tell me why it's being blocked nor does it give me an option to call off the dogs and allow the program internet access.

I tried Googling for help, but I can't find anything related to "Norton," "Plex," or "Modern UI" that seems to help. Any help here would be much appreciated!