Its even worse when you force Firefox to use wayland its icon doesn’t even show.
Edit: Oh since everyone now is confused; I only have the flatpak version of Firefox installed yet it doesn’t use the pinned icon and doesn’t even use the firefox icon under wayland at all.
i have no issues with flatpak, once i found out how to fix gtk scaling and theming issues on kde. here’s a link if anyone has those problems as well https://bugsfiles.kde.org/attachment.cgi?id=135846.