I’ve been experiencing an issue recently that may be related:
Add the Projucer icon to the dash/dock permanently via the “Add to Favorites” option, and see if the behavior changes. I believe a .desktop file must exist before the “Add to Favorites” option is available.
In my case, after adding the Projucer icon to the dash/dock, launching the application causes a second, lower-resolution Projucer icon to appear (this can be seen in the attached image – I’m using the dash-to-dock extension but this occurs with that extension disabled in the normal dash, as well). A bit of searching suggests that adding a WM_CLASS attribute to the Projucer.desktop file would fix this issue, but running
xprop WM_CLASS and clicking on the Projucer returns:
WM_CLASS: not found.
I’m running GNOME on Fedora, but I would guess that this behaviour isn’t any different in GNOME on Ubuntu.