System is using GTK4 version of pamac GUI
I suggest install pamac-gtk3 to replace this package
https://download.manjaro.org/kde/26.0.1/manjaro-kde-26.0.1-260114-linux618.iso.pkgs
pamac-gtk3 10.7.0-1
Unlikely since these packages have not been included in Manjaro Live ISOs since Manjaro 24.1 Xahea released October 2024