DMs need to chill

Okay guys. When I started I was told by the training videos and prompts, in drive thru, unless you have no more customers the window, you must always keep the window open to be able to connect with custys right? Only certain circumstances can you close the window. I swear our DM just makes up some stuff when she doesn’t like something, very nit picky. So apparently, we just got told we’re supposed to close the window even with a customer there? Is this correct and they changed this recently or???