SDDM resolution

Hi Does anyone know how to change the login resolution? Since installing a Radeon, the login screen has got large fonts, looks almost like 1024*768 whereas my desktop is 1920*1080. I've tried system settings and that only seems to allow me to change a theme in "Startup and Shutdown/Login Screen (SDDM)" I've tried "Breeze" and "Breeze for openSUSE" and I can;t see a way to change those themes thanks regards Ian opensuse:tumbleweed:20221120 Qt: 5.15.7 KDE Frameworks: 5.100.0 - KDE Plasma: 5.26.3 - kwin 5.26.3 kmail2 5.21.3 (22.08.3) - akonadiserver 5.21.3 (22.08.3) - Kernel: 6.0.8-1-default - xf86-video-nouveau: 1.0.17