Created attachment 180487 [details] screenshot1 STEPS TO REPRODUCE 1. open Dolphin 2. observe Dolphin icon in the apps launcher, task manager, task switcher (alt+tab) and in the window decoration 3. OBSERVED RESULT as we can observe in the attached screenshots, there are two icons for Dolphin EXPECTED RESULT just one icon SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 6.3.4 KDE Frameworks Version: 6.13.0 Qt Version: 6.9.0 Graphics Platform: Wayland
Created attachment 180488 [details] screenshot2
I'm not seeing a bug in Dolphin in git-master on Solus. There is a new app icon for Dolphin, with the stylized dolphin in it. This is now used in the task managers, and app menus, to represent the application (similar to how Firefox uses their fox icon). Folders within Dolphin will still use a blank folder icon by default, as before. This is expected. In screenshot1, I see the new, expected app icon everywhere except in the titlebar of Dolphin. On my system, I also see the app icon in Dolphin's titlebar. In screenshot2, this is also showing the expected icon. It's simply the default folder icon. It seems what you're seeing is by design.
Is the old icon "expected" in alt+tab menu seen in the screenshot2? I don't think so, it's an inconsistency. And I also see the old icon in the titlebar on my neon unstable running git-master.
This was fixed in https://invent.kde.org/system/dolphin/-/commit/1525c874f7578332b6f44cae727ff23d4c7bbcd6.
Backported the fix to 25.04.1 with https://invent.kde.org/system/dolphin/-/commit/c0a0060b4bd183ca6a6794ab2c1921c57430e06b.