After logging in to MyBT and selecting the personal details link, I am shown a "Please upgrade your profile" page where I'm asked to "Please take a moment to upgrade your profile". A form asks for an email address, a second field to confirm the email address and my password. After supplying a valid email address and entering my password the page reports:
"Sorry there was a problem saving your changes Please try again."
on trying again the page reports:
"Sorry, your password is incorrect. Please try again."
My BT ID is an older ID not in the form of an email address. Similar posts suggest this may be the reason but I have not seen any solutions to fix the issue.