To test the water, I put a small amount into BTC Interest account on June 19. Daily interests have been paid as promised. A few days ago, I moved the fund from BTC Interest account to BTC Primary account, and tried to withdraw. Then I got "incorrectly credentials"  error.  I have two-factor enabled on the account. I am sure I have entered the two-factor code correctly. I have send support an email and waiting for their reply. I will update here as things unfold.