Can't access forums on phone while on mobile data

[devel]

This is a strange thing that happens, and I have no idea why I can't connect to forum.rigsofrods.org. As soon as I connect to wifi, everything works. It's not a data issue because I can access any other website completely fine. I'm also able to use the phone as a hotspot, and the forums work completely fine when I connect to the phone with my laptop. I use Boost if that helps