No, this
1 Cpu struggling to play some high res mp4 video - #32 by omano
2 Login screen shows: file:///usr/share/sddm/themes/breath2/main.qml: No such file or directory - #2 by omano
3 Login screen shows: file:///usr/share/sddm/themes/breath2/main.qml: No such file or directory - #8 by omano
Here a fourth time
Set SDDM theme to Breath in System Settings / Startup and Shutdown / Login Screen (SDDM).
Does it fix the issue?