Cant no longer view Ring doorbell camera on Samsung Smart tv

Ok, so when my Ring doorbell was first installed all I had to do was say ALEXA SHOW FRONT DOOR and hey presto up it popped on the tv screen, this was a really old Firestick and it still works fine on it but BUT only if I now say ALEXA WHO'S AT THE FRONT DOOR !! But if I say the original command of SHOW THE FRONT DOOR it replies SORRY CAMERA'S DON'T WORK ON THIS DEVICE. Now using a slightly newer FIRESTICK it doesn't respond to the original command and the command WHO'S AT THE FRONT DOOR gets the response I'M NOT QUITE SURE WHAT WENT WRONG??????? I have recently bought a new Samsung 4k tv and a brand new 4k FIRESTICK when I ask both commands I get borh replies, I assume it's the command wording that's wrong, I am severely disabled, not good with technology and need things explaining idiot proof, I've contacted Amazon but they cant help as they won't admit it's THEIR equipment at fault, everything they suggested makes no difference at all, I'm praying someone can help me as I really need to able to view the Ring doorbell camera on my 2 tv's.