Video issues during FaceTime calls on Apple TV

I have an Apple TV 4k and had been using it for Facetime calls using Continuity Camera and an iPhone for the best part of a year with no problems. However, about a month ago, it stopped showing the person I'm calling's video on screen, although I could still hear their audio. The caller's camera is switched on and they can see their video in the corner of their screen. I have tried making Facetime calls to two different iPhones and a MacBook using the Apple TV, but the same issue occurs, and all three devices are able to make calls to my Macs/iPhone without the issue occurring.

I am running an up to date OS (tvOS 18.5) and have tried restarting the Apple TV, but the problem persists.

Any help would be appreciated.

[Re-Titled by Moderator]

Original Title: Caller video not showing on Apple TV Facetime