Multiplayer not working when hosted

So basically I have made a multiplayer card game, everything following the chat tutorial.

I have exported the project and hosted it on my computer and have setup appropriate routing on my modem.

To test the working, when I run two instances of the multiplayer game through a different computer on same LAN, everything works perfect.

Here is a workflow :

1. Host connects and joins a room, waits for peer

2. Peer connects, joins the same room

3. Soon after joining, peer and host both receive a notification (opponent arrived) via "On Peer connected"

4. Peer requests host to deal cards and goes on

When I use a different WAN (say from Uni or work), and login to the website. the "On Peer connected" never seems to occur. Both host and peer keep waiting forever, but they never receive "ON Peer connected" message

Just an update, using Firefox I enabled the web developer console and saw the following message:

ICE failed, see about:webrtc for more details

You need to make sure there isn't NAT or some kind of networking configuration that blocks peer-to-peer connections. Such setups are actually pretty common, especially in offices (and large-scale networks like a uni campus wouldn't surprise me either). There's more information about this in general in Multiplayer tutorial 1.