I can use FaceTime on my iPhone no problem but my MacBookPro (fully updated) has never been able to use it with same Apple ID

I can use FaceTime on my iPhone no problem but my MacBookPro (fully updated) has never been able to use it. They both point to the same AppleID & that ID works for all other Apple apps fine. For some reason FaceTime won't even let me log in with the correct ID. It'll tell me straight away if it's the incorrect ID, but if I try with the correct one it'll think for a bit longer but still eject me & I'm left at login window. It's the same on my older MacBookAir. Any help massively appreciated.