UPnP Not Working Through Ethernet Switch

Hello, first off, the system I am running:

Hardware: Raspberry Pi 2 Model B
CPU: 900MHz quad-core ARM Cortex-A7
GPU: Internal CPU Simulation
Storage: External USB 3.0 2TB Freecom drive (640 MB/s) Bus-powered
Power: 5V 2A Wall Socket charger (required for Bus-powered storage)

My network arrangement has my PC and Pi plugged into a Netgear GS105 Ethernet Switch, the input of which is routed through the house’s main power line (same setup I had at my other house, which worked ?!?).

For whatever reason I no longer have the Pi listed under Universal Plug ‘n’ Play in VLC player on the PC, where it used to be, despite the Pi having network access, the same settings, same setup and the same arrangement on PC as well.

Unfortunately, I have no way of testing without the switch as I only have access to 1 ethernet port in the room (hence the switches existance) so I am limited in the information I can give on tested configurations, otherwise I would have tested beforehand.

My hope is that someone may be able to recommend another way of streaming media files from OSMC to the PC so I am able to watch/listen to them on there, the Pi isn’t plugged into my HiFi, so it would be a huge inconvenience to have to constantly switch between them.

I use the Pi as a server for files, both for work and as a digital backup/filestore for my movies, tv shows and music which I have ripped from disc, so most of my stuff is on it, so I am in need of a way to access them easily on PC.

Any ideas?

You could just enable the Samba Server (Available to install from the App Store) and then map a network drive. This won’t use UPnP as you originally requested but the PC will then be able to see the contents of the Pi.