Automatic login + screensaver

In the Users and Groups preference pane, I am identified as the ADMIN.

I have  assigned Automatic login to myself. I very seldom switch my iMac off, preferring to have the screen saver show images from my Photo library. 

Since upgrading to Monterey, my iMac reverts to the login screen when I am away from it for a while, so I have to login again. Also, I miss seeing. my photos, since the screen goes dark rather than showing my screensaver.

Even my designated hot corner does not invoke my screen saver. I just get  the blank black screen.

Biandar