One Plus 7T wont allow youtube and facebook on data

Did you purchase your device from T-Mobile?  Are you running the stock T-Mobile or NA/Global firmware?  

Tangledtop wrote:

My phone won't connect to YouTube, Facebook or Outlook on data. I can get onto games and other sites. It says its dangerous to continue I click on advance anyway and then it says there is a problem. I checked Google chrome security and it's all good. Download Android internet and still can't get on. Any ideas? When I'm on wifi there are no issues and I can get onto other sites on data. 

This sounds like android rejected their security certs. You should be bale to go in to it and remove them so they can be repopulated.

Also a side note. Downloading android interent was most likely a bad idea.

you made sure all of the apps having issues are fully up to date?