Just a comment.
Suggest you respond to the moderator for further help.
However, from all you screen shots it appears that you are using IE11 in “private mode”, which isn’t a good thing, as you are rejecting all the “good” cookies.
Thanks for all the help offered. None of it worked.
Then It Came To Me.
Take BT OUT of the Trusted Sites List in IE11
Presumably you also took advice from the offer of moderator help, and you have solved the problem.
You appear to have indirectly cleared browser history, however, if you have set IE 11 to clear history on exit.
I figured it and I never clear my browser cache on closing.
But here's the part no one explained.
Why should I not put BT Mail or any other BT site in my trusted sites zone?
This guy is laughing. I agree. Much better than the Family Grim picture.