Certain websites will not open
I am having an issue with content loading very slowly (websites like facebook and instagram) or not loading at all giving me a "failed to open page" message on other websites (facebook and macrumors). I am getting very weird results.
Speed tests show full speed of the modem being detected. I have reset the modem to factory settings without any success at resolving the issue. I first thought it was my router, but I hardwired my computer directly to the modem (NVG589) and issue still persists.
Yesterday morning after a factory reset of the settings, facebook.com loaded fine but a bit slow. Yesterday evening could not load facebook.com at all, it seemed like it was trying to connect but would not. From my iPhone I am able to use the facebook app but photos load slowly, similar affect on instagram. I still have no success connecting to macrumors.com on either computer nor iPhone. I haven't found other sites that do it, but that is what I have noticed so far.
Please help with any ideas