I want to explain. Couatl does not start automatically after I start MSFS, and it still does not appear in the taskbar.
But that's a known MSFS bug! It doesn't start automatically for me as well, maybe one every 5 times or so, but not just couatl, all the add-ons in the EXE.XML ( Fenix, Honeycomb, etc. ) don't start automatically, the whole EXE.XML get skipped for some reason.
The issue is well known on MSFS forums.