The “toggle” option has been broken since the SU5 update. Carenado has been informed about this and the other issues that stopped working since SU5. They stated they are working on an update which has yet to appear for the Mooney. Their other aircraft have been updated since SU5 but we’re still waiting for the Mooney update.
You can search the forums if you want to know more things that broke since SU5. There’s several topics on the subject.