Comment # 15 on bug 954419 from Josef M�llers

As David Kerkhof writes in comment #10, you need to explicitly add pam_mount to
/etc/pam.d/sddm:
pam-config --service sddm -a --mount

Once that's included, it works, so it's not a PAM issue. I'd try for YaST which
should add pam_mount to the relevant /etc/pam.d entries.
As an alternative, one could require sddm to always include pam_mount in
/etc/pam.d/sddm. It does not hurt if it's there and you have nothing special to
set up, after all, it was there in /etc/pam.d/{login,sudo,xdm}.

Reassigning back.