The television series “Georgie & Mandy’s First Marriage” is a spin-off of a series that is already a prequel, something that typically does not draw in an audience. With sitcom mastermind Chuck Lorre behind the third installment of the franchise “The Big Bang Theory,” and bringing back many fan favorites from the prequel “Young Sheldon,” it seemed like the show would likely live up to the expectations placed on it … right? Not quite.