It seems that this bug only happens when the user tries to do that for the first time since installation. But basically the issue is: You try to change one of these two types of screens, it asks for a password, then it doesn't change anything, so you try to change again, enter the password again, then it actually changes.
What page are you on? What are the "Authentication Screen and Presentation Screen"? Can you please write steps to reproduce?
Created attachment 176542 [details] Video of the issue of having to enter the password twice to make the change. This issue only happens on the first time, when changing the Authentication Screen (SDDM).
Ah, the login screen page in System Settings. Cannot reproduce with an existing user account.
You can also reproduce the issue with org.gnome.Boxes flatpak.
*** Bug 508617 has been marked as a duplicate of this bug. ***
I was able to reproduce this on a new user on a Cachyos VM running 6.4.4 I'm not able to reproduce this exactly on a freshly installed Neon Testing VM or with a new user on git-master. The results were the same on both. This bug is resolved, but there's another bug with the thumbnail that I'll create a new report for. - Changed the background of the default Breeze SDDM theme, clicked Apply Observed: The thumbnail in the Settings screen did not change - Rebooted Observed: The new background *was* correctly displayed in the actual SDDM screen - Checked the SDDM settings Observed: The thumbnail still shows the default Breeze background When I went to Behavior, and checked Automatically log in and Apply, that change was saved. So it looks like this has been fixed in 6.5.0. I'm not sure if it will be backported to 6.4.5. Feel free to reopen this if you still see this bug in 6.5.0. Thanks!