I agree that I also have been unable to sign message from address which I hold in my blockchain wallet. Do you mind sharing screenshots of your conversation with 2double0 publicly or maybe share with someone trusted (i.e actmyname if he doesn't minds)?
Why not you bro? You too are a very trusted member of the community as per I see.
I can share the screenshots of the telegram conversation with you via PM. Let me know if you are willing to verify it.
hacker1001101001 sent me the chat screenshots and it checks out with he said in his previous post. He also sent me screenshot which verified the 2double00's telegram id. Hope this rules out the 2double00-hacker1001101001 part unless anyone have more questions to ask.
Feel free to PM me for screenshots (but will check out with hacker if he is comfortable with it or not).