Adobe Launch - Submitting Private Key for Self Hosting via SFTP

I'm trying to configure Adobe Launch to publish to my self hosted SFTP server.

Can you help with uploading my ssh private's key?

I've created ssh keys and then wrapped them in the gpg encryption wrapper as outlined here: https://developer.adobelaunch.com/api/guides/encrypting_values/

However, I've ben unsuccessful at submitting the keys via the launch "adapter".

Keys created as Open SSH (as referenced in the official docs) get stuck in “Pending”. ( https://docs.adobe.com/content/help/en/launch/using/reference/publish/hosts/sftp-host.html )

Keys created as PEM (as referenced in the medium doc) “fail”. ( https://medium.com/launch-by-adobe/configuring-an-sftp-server-for-use-with-adobe-launch-bc626027e5a6 )

I have verified that both Open SSH and PEM keys work correctly with our SFTP server and that the server is publicly accessible.