Once you're connected, click the little wrench/spanner icon on the far right to display the contents on the server. If that works (and it should), it's important to mark your web root - the little folder icon with a globe on it.
More info:
https://jalbum.net/help/en/jAlbum/Upload#Accounts
You might also have better luck with a different protocol. On my web host, I found that
SFTP was more stable and reliable than the others. Or try one of the simple, non-encrypted choices, like one of the plain
FTP choices (there are two of them).