Description of problem:
The firefox-wayland.desktop file doesn't have browser windows grouped under it. They instead show up under the firefox.desktop file.
Both desktop files are incapable of launching additional windows.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Run "Firefox on Wayland" (firefox-wayland.desktop)
2. Observe windows actually grouped under "Firefox" shortcut (firefox.desktop)
3. Middle Clicking "Firefox" and "Firefox on Wayland" present an error, instead of opening additional windows
Error message about the firefox profile being in use
A new browser window is opened
This can be solved by adding a --name parameter to each Exec line in firefox-wayland.desktop, to match the .desktop file name. For example:
Exec=firefox-wayland --name firefox-wayland %u
*** Bug 1585492 has been marked as a duplicate of this bug. ***
Fixed by firefox-60.0.2-1.fc28