Question re:upnp and VPN

I notice on my Kodi box (Tx3), if I have my VPN (PIA) enabled, I cannot see the files on my upnp server (both are running kodi 16.1).

If I disable the VPN, it works fine. Is there a work around for this, so I can leave the VPN enabled all the time and still see my server, or do I have to continue to exit and enable the VPN for other uses?

Thanks