I have exact same issue as OP here
I'm on a Windows 8.1, using Git Bash I type:
ssh git@bitbucet.org recovery_codes
Afer typing in password I get the following:
Earlier today I had one more recovery code stored, used it to log into Bitbucket, then tried to add my new phone to as a 2FA device (do not have the old one) and it promped me for another code, so I did try to get recovery codes via ssh with output above.
Since I work on these repositories once in a few months I used to just recover my codes when I ran out of them, but now they come blank for some reason. Tried at least dozen of times already.
Thankfully I can still work on a repo, but I would like to get access to account settings as well.