Turn on checkbox mode > Check some images & select (do not check) some more images like this:
Press Enter to view the selected images in the viewer. The star icon in the top left corner is invisible & the "Mark file" entry in the context menu is not checked, I have to press M to select any images to make the star icon visible, should it be visible automatically?
Click on 1.jpg, the star icon in the top left corner is invisible & the "Mark file" entry in the context menu is not checked until I move to the next image. Should the star icon be visible at the first image?
DO12.0.12+
Preferences\Viewer\Behavior\Check for marked pictures when viewer is opened: Checked
Preferences\Viewer\Behavior\Save marked images to a file collection: Unchecked
Please have a look at it. Thanks!