Hello,
I am having the same issue on a different site (where I even still have my default style called "Default"). It is also not resolved on this page.
Could you please look into this issue as now I'm having this problem on a clients site? I added the second domain/site to the info, same username and password.
For the FTP, it's a bit more complicated so I couldn't enter ftp info in there, but if you reach out to me outside of the forum, I'll be glad to give you login credentials there too.