pamac-gtk3 and pamac-gtk have always been marked as conflicting packages since the packages were split in 2023
$ pamac info pamac-gtk
Name : pamac-gtk
Version : 11.7.2-1
Description : A Package Manager based on libalpm with AUR and Appstream support (GTK4)
Conflicts With : pamac-gtk3
$ pamac info pamac-gtk3
Name : pamac-gtk3
Version : 10.7.0-1
Description : A Package Manager based on libalpm with AUR and Appstream support (GTK3)
Conflicts With : pamac-gtk
[Stable Update] 2023-07-10 - Known Issues and Solutions
2023-07-10
Pamac GUI theme does not match theme for Xfce
pamac-gtk
11.0.1 uses Gtk 4 that is not supported by Xfce
user can replace pamac-gtk with pamac-gtk3pamac install pamac-gtk3
[Stable Update] 2023-07-10 - #164 by nikgnomic
@Nerdgasm If you install
pamac-gtk3
to replacepamac-gtk
and confirm it works for KDE, known issue can be edited to include KDE