External monitor HDR turns off after sleep on a Mac

After a sleep or a lid close, an HDR monitor on a Mac can come back dim or oversaturated, either with the High Dynamic Range switch turned off or with it still on while the monitor has dropped to SDR. The write-up covers what people report going back to 2020, how to tell which of the two cases you have, and the fixes that work without an app. It also says where my app does not help, because it cannot see the second case.
https://manydisplays.com/mac-hdr...
If you run an HDR monitor on your Mac, I'd like to hear which model and whether it keeps HDR after sleep.