Home Theatre picture is flickering

With HDMI 2.0 ports on the Arcam, your video settings may need tuning so that the video stream stays under the HDMI 2.0 bandwidth limits. Please check your video settings on Apple TV. Set Chroma Subsampling to 4:2:0 if not already set that way, then all other video settings should stay within HDMI 2.0 limits. This would be fine for all streaming video, as all are encoded with 4:2:0 anyway. Also check that all your HDMI cables are rated for 18 Gbps or better. (4:4:4 would exceed HDMI 2.0 limits for 4K HDR10@60Hz, or 4K Dolby Vision@50/60 Hz.)

I have read that Arcam offers an HDMI 2.1 upgrade path, but you’ll have to send in your unit (through dealers), according to posts on AVSforum.com [1] [2]. For use with HDMI 2.1 ports on devices on both ends of the HDMI cable, bring cables rated for 48 Gbps to ensure that the cables are not the bottleneck.