Login problem: Can't connect to Xbox Live

Yesterday I started having problems connecting to Live. Just in case, I factory reset my console, I contacted an Xbox ambassador and he told me to erase my profile and then login again. It worked.

Today, I’m having the same problem.I have made an alt account, and that one works fine. So its a problem with my main account

Now everytime I turn on the console I have to erase my main profile, re-login, input my password manually. This is a PITA.

Any known solution to this?

I have almost the same issue, except it usually fixed itself when I signed out and back in again. Its confusing because my ISP is rubbish too, but there are different symptoms when that happens.