You're right. From what you've said that makes no sense. It would either be tidaly locked like Epyk said. Or be orientation locked which would give days & nights of 6 months between sunrise and sunset.
theres another type where the earth stays doesn't rotate and one day would be 365 days since sun would only cross all of the earths surface once a year, but i dont get how we would still have 24 hour days with no rotaion
Well at the end they were talking like it had stopped and it would be 6 months of day and 6 of night which makes sense. I think I just started watching it at a wrong time and condemned it too soon. They were making it slowly stop but didnt do a good job of describing that.