The only possible reason I can think of that if you start couatl the menu says it's not running, is because you might have another copy running from a previous session that is preventing the new one to complete its startup.
So, maybe, the only issue is that you never had to start it manually, because it was started by the sim automatically, as it normally is.
Or, the sim crashed for other reasons, so it couldn't send the "quit" Simconnect command to the Couatl engine, which didn't close from a previous session, so the new one can't start.
Just check with the Task manager, and be sure there are no instances of Couatl_MSFS.exe still running before starting a new one. If there is one, terminate it and start it again.