Talk not loading via web UI

Hi,

I have a Nextcloud version 21 installed and everything is working as expected so far. Today I tried the Talk feature and could send message via chat but I couldn’t make a video call.
I have a screen popup and spinning plate. The chat never loaded.

I Nextcloud instance is behind a pfSense firewall and I was wondering if I need to open a port for the communication work? We tested the chat with me at site A and colleague at site B on separate network and IP ranges