AppleTV 4K default resolution doesn't match 1080p HDTV resolution
When I use my AppleTV 4K with my Sony 1080p-capable HDTV with a direct HDMI connection between the AppleTV and the HDTV, whenever I start the AppleTV, instead of defaulting the resolution to 1080p, as my other components do, the AppleTV defaults to 720p resolution and I need to go into the Settings and manually change the resolution to 1080p SDR. The AppleTV then informs me that 1080p SDR is able to be used on my HDTV and asks if I wish to continue, which I do. Then, after shutting down both components, when I next wish to watch AppleTV, the default resolution is again set to 720p.
How can I get the AppleTV to stop using 720p as the default on a 1080p-capable HDTV and not have to manually change to that resolution every time I want to watch AppleTV? I even wen through the whole process os set-up after resetting my AppleTV, but this did not change. It had worked properly earlier but, after my AppleTV froze and had to have a hard reset (where the power cord was disconnected and then, after 30-60 seconds, reconnected) the default resolution changed to 720p.
Thanks.
P.S. I asked this question in an earlier discussion, but that seems to have been deleted from my subscriptions.
Apple TV 4K, tvOS 12