I'm assuming if I click Backup, it will backup current state, not restore??
Yes, don't tap backup. You will lose your entire backed up data. Also disable auto backup until the problem is solved.
Try reinstalling the app. This often helps.
We have authenticated login, encrypted archive, rsync and multiple transport protocols (including HTTP, WebDAV, FTP and SSH/SFTP) in one tool: rclone. It supports local filesystem and a number of cloud storage. Additionally it does have all of the four mentioned servers builtin. It means that all you need on both sides is rclone. No root access is necessary ...