Ivan, do you happens to use GNOME on Wayland?Sure, I can come up with workarounds myself, but at that point what is the point of using Love2D.
Because I kinda recognize some of them and they probably specific to wayland implementation of gnome, which is can of worms on it's own.
As slime mentioned about icons, this is wayland thing. As far as I understand, wayland doesn't have currently sane way to provide titlebar icon. You need to provide .desktop file with icon for this to work. Even Godot's wayland implementation currently struggles with that, because this is wayland thingy then love.
Do you mean title as "Mystery Mysteries" or as titlebar with close button, minimize, etc?The Love2D application title is not set by default in the top bar on Linux
If this is titlebar, then yeah, this is again wayland thingy. Some wayland compositors might provide server side decorations so there love window will have system titlebar, while other compositors like gnome don't use server side decorations, so programs themself need to draw this. As far as love appimage go, titlebar there is working. If you installed love from somewhere else (for example, flatpak version from flathub) then that version might not have using libdecor or something like that for having titlebar.
As other people mentioned, yeah, this is how this work with pretty much on many OSs. When you make window fullscreen, then you can't move around it and there usually no titlebars (tho, it might be possible that some window manager might work differently)- On Microsoft Windows 10, the window title is completely off the screen after calling love.window.setFullscreen
It is not possible to move or resize the window using the mouse after calling love.window.setFullscreen