SSH Submodule only fails to clone

[gregorykrol]

I have 2 repositories A and B.

B is a submodule in A.

HTTPS cloning works without a problem.

SSH cloning (recursive) succeeds until it begins cloning/updating/initializing the submodule B.

We get the ubiquitous error message:

"Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists."

Things we've verified:

1. Users have Read access (even admin access fails)
2. Repository exists
3. ssh-add has the identity confirmed
4. ssh key is in users settings page
5. ssh -T git@bitbucket.org succeeds
6. url in .gitmodule file is correct

Tried everything on https://confluence.atlassian.com/bbkb/permission-denied-publickey-302811860.html

Tried everything on stackoverflow. Spent a couple hours trying to figure this out, reading through questions here, stackoverflow, and git docs. Asking a Q as a last resort.

I'm out of ideas as to what to even ask, since we've checked permissions, configuration, and urls all appear to be correct.

I'm starting to think submodule cloning is https only supported