So I can join my server through my mobile device, but I can't on my computer (where I'm hosting my server as well). I thought that it's not possible to join through where I'm hosting it, but I realized that it is not true. My friend, who is using a weaker device, hosted a server on his laptop, and he could join his own server on his laptop while it's running. If you experienced a similar problem and solved it, I would be happy to know how you solved it. Thank you so much!