I managed to debug what was going on and I discovered that NodeBB was doing everything correctly and that passport was working as it should, sending the right URL to redirect to, but my HTTP Reverse Proxy (In my case a IIS server) was somehow rewriting the Location header to use the servers domain.
Managed to fix this by going into the Server settings, Application Request Routing and on the right going to the "Server Proxy Settings", and once there unchecking the "Reverse rewrite host in response headers" checkbox.

@gorgiselkov The integrated Node.js web server? I believe you shouldn't do that, and as the guide states, you should always use a proxy server like, in my case IIS, but as the official guide states, Nginx.
You should follow this guide in case you haven't (depending on your Servers OS):
https://docs.nodebb.org/installing/os/

@Ne-Ho I believe I have managed to fix it in my custom fork of the Material theme:
https://github.com/geferon/nodebb-theme-material

So far it works well on my forum without the page not refreshing/etc

@Ne-Ho Okay, I do have the chat Issue, i'll try to fix it, but I don't have the navigation toggle issue? I mean, is the sidebar on the left not positioned correctly for you, or what exactly is the problem?

@Ne-Ho Yes I got it already but thanks.
I've already almost managed to fix it on my end, just doing final touches and i'll publish it before going to bed.