Bug in webmin ftp password for scheduled backups

I try to enter the correct ftp password for the user, and, I get a message from webmin:

Failed to save backup : Invalid characters in FTP server password

In testing the various characters in the password, one of them is a '@'. Which is perfectly acceptable in a password, and works fine from the command line. It also works from Virtualmin backup. It just doesn't seem to work from webmin backup.

Using special characters is a required practice at our company, and, we have a few dozen machines all logging into the backup host. We'd have to change them all, and a few other things so prefer to keep the password the same.

Can webmin be fixed to allow special characters? At least the @