Intermittent problem of losing underscan setting

Alas, there will be no solution appearing as I'm giving up.

I put a lot of time into various tests and dialogue with the Apple agent including, for example, making a two-minute video of me carefully replicating the problem. The issue was eventually referred to some further engineers. The agent has now come back to me and asked me to conduct a further, extensive, and very time-consuming test - to backup my data, erase my entire disk, install Monterey, and see if the problem is still there.

I've already told them it wasn't there in Monterey, and that I'm on a slow rural broadband. Their request is unreasonable and this is a test their engineers should be doing, not me. That is, they should replicate the issue in Ventura (there are plenty of people who experience it, and my video shows exactly how it happens, and I've given them the exact TV/monitor make and model) and then do the roll back to Monterey themselves.

I can't afford the time, nor take the risk, so I'm giving up. Now, I'm not only Grumpy by name but also grumpy as a result of the responses from Apple.

Thank you. I contacted them via chat, and was put onto a phone call with a senior advisor, who spent some time with me going through various tests and troubleshooting, gave me some more to complete, and we are now communicating by email. It seems it is an obscure problem as it doesn't occur with two other monitors that have hdmi inputs - though, when connected those monitors do not have the underscan adjustment in the Mac display settings.

I didn't have the problem with Monterey and the same TV/monitor as I have now, so I do think this is an obscure bug with Ventura. Given that other monitors work (though, they are not suitable for my everyday use), I'm waiting to see if the advisor decides to escalate it further.