My first thought is the router/modem of your ISP may be the culprit due to security settings flagging things wrong--the problem is, if it is in fact the culprit, that's going to be a pain the the butt to fix, especially if you're not well versed in technology. I work in tech and if that was in fact the culprit and I were experiencing the same, I am not confident I could fix it for myself.

When you browse through your phone, are you connected to wifi or cellular data only? If you connect to wifi, does it ever occur when you are on cellular data only (ex: you are browsing when you are not at your home)