Sounds similar to my problem. At some point my Microsoft account was linked with an old startup email as a backup. I've updated it to fully remove it and set my gmail as primary. Yet I am still receiving subscription/billing emails to that old address, which fortunately is being forwarded. The UI simply does not reflect reality.

When I contact Support I tell them the whole problem at the start. Then eventually an agent comes on and asks me a dumb question. If I don't respond quickly enough they close the chat and the whole process restarts.