Check very well on what data plans you did on the MTN subscription because you might have mistakenly subscribed for social media like Facebook, Whatsapp, X and all that. Be sure that such data subscription giving access to the internet doesn't support web browsers like the firebox, chrome and the rest which so, you can't access the forum but if you can access the forum but having issues only on the ninja.space web server then it must be a range of network issues which I'll advice you turn off your internet or flight mode your phone in few seconds to activate back your breached network of the MTN.
I saw your comment yesterday night but I was waiting for others to comment. Social Media Browsing would not allow you to enter forum and other websites. Even before I dropped this thread yesterday, it took me more than 2 hours because of bad network. Even the social media you are talking about is loading more than hour's to open.
You can see the data strength. Network quality is good sometimes but the signal strength is very bad.

I don't think social media subscription is up to 5G and 11G. And it should be MBs.