Frustrated with site not loading for users randomly, possible DNS resolve issue

I posted a while ago with the same issue here, but I am still having some issues. I'm still pretty new to all of this, and server side stuff is definitely not my strength.

I keep track of what people say when my site is used on Reddit by searching by domain pretty often, and it still seems the site isn't loading for some users, but from reports, there is no patter whatsoever. Browser, OS, country, etc. It's all completely random. Having them clear browser and DNS caches isn't fixing the issue either.

Might anyone have a little insight on what it is that could be causing this, or ways I can test to see wherein lies the issue? Thanks in advance for any help offered.