Daniel or Jennifer,
I would also be interested in what combination either of you found to work.
I have also run into the same issue and I am trouble shooting. I have came across other SFTP issue doing the same as you have, trying each and every combination in HOPES one works.
I can say the SFTP or FTPS 'functionality' (and error logging) of Automate is extremely frustrating, I have expressed that to support.
I also find multiple post with folks having issues and rarely see a resolution.
I would like to second the comment expressed by customer. I have also brought this up before as trouble shooting any FTP / SFTP / FTPS is impossible with the error logging.
Today is perfect example, I am trying to change and existing SFTP/SSH connect per customer changes for cipher. The connection is failing and I have 'error 7' to work with. Really? I have never understood how any of these FTP function make it through testing.