Unable to access Twitter, via app or browser just on my iPhone

Hi,

This began a couple of days ago, I was unable to refresh Twitter via my app and I just assumed it was a problem with Twitter. Now two days later I'm still unable to refresh Twitter and am unable to access the home page via browser. This happens on 4G and on Wi-Fi. I'm getting access via my Mac on Wi-Fi with no problems.

I'm guessing somewhere either Twitter is blocking my iPhone from accessing the server, or my iPhone is blocking access to the Twitter server. How can I resolve this?

Cheers,

Sam