Why won't my Apple Watch record a nap even when using Sleep Focus?

An earlier thread had people discussing widening the window in one's sleep schedule in order to get the apple watch to automatically detect sleep if one took an evening nap before bedtime.

My problem is more basic: Even if I explicitly put it into sleep focus because, for example, I'm going to take a 30 minute nap in the middle of the day, it will not record sleep. Of course, auto-detecting and tracking sleep, like my partner's Oura does, would be great, but I understand that's not a feature of the Apple watch. But why will it not record a nap even if you set it before the nap to to sleep focus, and turn off sleep focus when the nap is done?

Based on the earlier thread, the only thing I can think to try is to set my daily sleep schedule to something like 10pm to 9:59pm to make it "available" to record sleep when I put it in sleep focus at any time of the day - but that seems like a crazy design - and even so, I'm not certain it can calculate and add two bouts of sleep.

I called Apple and the person assured me that, using sleep focus, the watch (Apple Watch Ultra 2) would record a nap anytime - but it simply does not. Has any one figured out a kludge to make it record a daytime nap at any random time, as long as you turn on sleep focus before the nap?

[Re-Titled by Moderator]