AWX and Credssp server did not respond with pubKeyAuth info auth was rejected

I’m working with Windows machines via WINRM and Credssp. With AWX running on a RedHat server.

My playbooks work from the command line, but when I run them from the AWX server they fail with:

WINRM CONNECTION ERROR: The server did not respond with pubKeyAuth info auth was rejected

It seems like the credssp module never gets loaded from within AWX.

Any help would be appreciated.

thx
Kevin