sddm-greeter: SDDM login screen starts with a flashing white screen a few times before displaying the login page (greeter)

[rafi-gh]

Every time I start up my system and enter the SDDM login screen, the entire screen flashes white a couple times quickly before stabilizing and displaying the actual login page. This also ha
ppens when I log out of my account. The flashes are very bright and could possibly be problematic for some. Below are the logs generated by sddm-greeter on boot:

sddm-greeter[3845]: QObject: Cannot create children for a parent that is in a different threa
d.
                    (Parent is QGuiApplication(0x7ffd533a2a70), parent's thread is QThread(0x
55eca7a40270), current thread is QThread(0x55eca7bc3930)
sddm-greeter[3845]: QObject: Cannot create children for a parent that is in a different threa
d.
                    (Parent is QGuiApplication(0x7ffd533a2a70), parent's thread is QThread(0x
55eca7a40270), current thread is QThread(0x55eca7bc3930)
sddm-greeter[3845]: QObject: Cannot create children for a parent that is in a different threa
d.
                    (Parent is QGuiApplication(0x7ffd533a2a70), parent's thread is QThread(0x
55eca7a40270), current thread is QThread(0x55eca7bc3930)
sddm-greeter[3845]: QObject::installEventFilter(): Cannot filter events for objects in a diff
erent thread.
sddm-greeter[3845]: Failed to find a Kirigami platform plugin
sddm-greeter[3845]: file:///usr/share/sddm/themes/breeze/components/VirtualKeyboard.qml:12:1:
 Type InputPanel unavailable
sddm-greeter[3845]: qrc:/QtQuick/VirtualKeyboard/content/InputPanel.qml:138:5: Type Keyboard
unavailable
sddm-greeter[3845]: qrc:/QtQuick/VirtualKeyboard/content/components/Keyboard.qml:38:1: module
 "QtQuick.VirtualKeyboard.Plugins" is not installed
sddm-greeter[3845]: libpng warning: iCCP: known incorrect sRGB profile
sddm-greeter[3845]: QQmlEngine::setContextForObject(): Object already has a QQmlContext
sddm-greeter[3845]: QQmlEngine::setContextForObject(): Object already has a QQmlContext
sddm-greeter[3845]: Failed to find a Kirigami platform plugin
sddm-greeter[3845]: file:///usr/share/sddm/themes/breeze/components/VirtualKeyboard.qml:12:1:
 Type InputPanel unavailable
sddm-greeter[3845]: qrc:/QtQuick/VirtualKeyboard/content/InputPanel.qml:138:5: Type Keyboard
unavailable
sddm-greeter[3845]: qrc:/QtQuick/VirtualKeyboard/content/components/Keyboard.qml:38:1: module
 "QtQuick.VirtualKeyboard.Plugins" is not installed
sddm-helper[6103]: gkr-pam: unable to locate daemon control file

I think the PNG error is caused by the user login image that was selected for my account (it disappears when I change this to just text). However, this image was taken from the provided list of images. The issue is improved without the PNG error, however, it still occurs so the problem is not resolved.

[rafi-gh]

It is worth noting that I am using SDDM with Wayland and Plasma.

[Vogtinator]

Maybe the Breeze theme thinks it should show the virtual keyboard, but it's not installed so that might be the white screen. You can try with qt6-virtualkeyboard installed.

[rafi-gh]

Maybe the Breeze theme thinks it should show the virtual keyboard, but it's not installed so that might be the white screen. You can try with qt6-virtualkeyboard installed.

That does not appear to resolve the issue.