Sporadic Video Drop Outs with Apple TV 4K

The device is an Apple TV 4K that’s about a year old. It’s connected to a Sony Bravia with a good quality HDMI cable. Everything has worked great until the last several weeks (maybe coincident with an upgrade? Not sure…). I’ve begun noticing sporadic bouts where video, but not audio, will drop — in this case to black. This generally lasts a few seconds, then video returns. Doesn’t seem to be related to a particular app. I’ve tried restarting (via the system menu), but have not yet reset. I don’t think it’s a cable issue, although I can probably swap one out and see if it makes a difference. Looking for any ideas, or if it’s a known problem. Thanks.