After upgrade to 15.2 time to startup from login screen to KDE being ready to respond can be 5 minutes. On 15.1 time was less than 20 secs.

Suggested commands do not seem to show any KDE startup information that is useful.

x64Cru_150G:~ # systemd-analyze blame
8min 40.609s fstrim.service
8min 22.759s mandb.service
20.826s backup-rpmdb.service
7.276s wicked.service
3.832s user@1001.service
2.511s systemd-udev-settle.service
1.251s lvm2-monitor.service
1.110s display-manager.service
962ms apparmor.service
723ms dracut-initqueue.service
716ms postfix.service
582ms firewalld.service
579ms systemd-udevd.service
549ms ca-certificates.service
472ms initrd-switch-root.service
470ms systemd-hwdb-update.service
249ms polkit.service
242ms backup-sysconfig.service
220ms upower.service
205ms ModemManager.service
203ms systemd-journal-catalog-update.service

x64Cru_150G:~ # systemd-analyze critical-chain
The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character. @13.896s
└─display-manager.service @12.785s +1.110s
└─systemd-user-sessions.service @12.743s +37ms
└─ @12.739s
└─wicked.service @5.461s +7.276s
└─wickedd-nanny.service @5.420s +39ms
└─wickedd.service @5.370s +49ms
└─wickedd-auto4.service @5.316s +52ms
└─ @5.312s
└─firewalld.service @4.729s +582ms
└─polkit.service @4.478s +249ms
└─ @4.409s
└─ @4.409s
└─avahi-daemon.socket @4.408s
└─ @4.398s
└─sys-fs-fuse-connections.mount @34.439s +3ms
└─systemd-modules-load.service @255ms +37ms

There is no info that I can detect in the Journal that tells me the reason for the long login. If the cannot be fixed I will have to abandon opensuse. Time is better after system updates, and I reboot that day. However, if system is off for several days then the login time returns to 5 minutes.