I am also have some trouble getting the code to fullscreen on the secondary display (the projector). I tried this method but it doesn’t seem to work.
https://discourse.panda3d.org/t/multiple-displays-one-viewpoint-per-display/12015/3
When I use this method, or a slight variation the replaces base.win, with self.win, called directly after ShowBase init. The window fullscreens but on the primary display, not the display that the window is on.
Any ideas?