To add to the mystery over this, here is something else from today. I was talking to someone else who has a two year old Samsung phone, (I forgot the exact model). On his phone the notifications were working in yet another, 3rd fashion. On his list of notifications, the top one on the list was always expanded and the following notifications under that were not. When he dismissed the top, expanded notification, then the next one on the list became the top one and expanded automatically. He said that is how his phone worked, he had not changed any setting.
That behavior is not quite what I had on my old Pixel, but it would be better than the way my S22 Ultra does it with all notifications collapsed unless you specifically click the drop-down arrow on each one.
There is a 4th way that was mentioned somewhere also where the notifications were not expanded by default but showed 3 lines so you see more about the notification. That would be somewhat better also. I have just started playing with the Good Lock app. Not sure yet it will be able to do anything about this issue, but it does have a lot of other features.