I try to use grsync to backup and restore data via LAN from a number of OS 13.1 Xfce laptops to a OS 13.1 Xfce Desktop.

grsysc:
**** default - Thu Mar 26 10:04:23 2015

** Launching RSYNC command (simulation mode):
pkexec rsync -r -n -t -p -o -g -v --progress -c -l -H -D -z -i user@suse-64.itw.lan:/home/ /home/user/backup/user

Permission denied (publickey,keyboard-interactive).
rsync: connection unexpectedly closed (0 bytes received so far) [Receiver]
rsync error: unexplained error (code 255) at io.c(235) [Receiver=3.1.0]
Rsync process exit status: 255

Using RSYNC without GRSYNC GUI works fine:
rsync -r -n -t -p -o -g -v --progress -c -l -H -D -z -i user@suse-64.itw.lan:/home/ /home/backup/user

Using grsync from a Gentoo system works fine. The Gentoo system uses "x11-ssh-askpass" to ask for for the remote system's password. OS 13.1 uses something else to ask for the remote system's password.

OS 13.1 ~/.ssh/known_hosts is 444 bytes. Gentoo's ~/.ssh/known_hosts is 189 byte.