If you previously printed the document and saved the document, If you open that saved file and make an other print and do not change any print setting. When you close the document Photoshop will most likely not ask if you want to save changes because you made no changes. Photoshop will close document that you close when there are no unsaved changes. If there are unsaved changes you will get a saving prompt.
Photoshop 2021 is doing that to me, too, particularly when I'm editing a doc in the Photoshop cloud. I make changes, such as collapsing layers --- a change I do NOT want to keep --- and then close the document, assuming that PS will ask if I want to keep the changes, and allow me to say "no".
Then it saves the changes without asking and I lose all my layers.