When I try to make plasma startup without login (automatically) it keeps asking for my credentials.
I'm afraid there isn't enough information in this bug to be actionable. Please read https://community.kde.org/Get_Involved/Bug_Reporting and add the missing information.
steps to reproduce:
select "automatic login" in the "advanced" tab of the sddm configuration module in the systemsettings.
At reboot the machine will ask for credentials again.
I'm experimenting with this but this is a eight years old Dell Lattitude E5500 laptop. I just tried on a much newer machine (also intel cpu) and there it worked as it should. If/when I learn something more I will tell here.
Can you run
and paste the output please.
To be extra sure I configured sddm to NOT login autatically and rebooted. After that I configured sddm to login automatically (also using the graphical tool in systemsettings). But the system keeps asking for my credentials.
When I run cat /etc/sddm.conf the output is:
Thanks for the update; changing status.
Just fixed today in https://cgit.kde.org/sddm-kcm.git/commit/?id=634a2dd1bef5dd8434db95a391300f68f30fd14e