clicking the green 'code' button in the github window
a dialog or info window pops up where the highlighting
together with the cursor stays 'above' the window, visible.
Different clicking e.g. firefox'es menu a dialog appears
where the cursor stays visible, while the highlighting
hides behind the layer of the dialog.
Observed in actual ubuntu with GNOME and Kali with
XFCE4 desktop.
Hope someone will like to improve and hope it's not too
difficult.
And again, thank you very much, very useful utility. :-)