I can't undo because I've saved the map - but I haven't saved the map

I saw this old thread about not being able to undo after saving: Undo history resets after save - #12 by ddoucet_BLE and could not agree more that Undo is pretty vital.

Unfortunately the issue persists in UE5.1.1, and not only that, I’ve turned off auto save and yet still run into this problem even if I haven’t hit save the entire time I’ve been working. So my question is, what exactly is being saved and where can I turn that off? I’d find it less awful if I could at least be the one who determines when I want to save and wipe my undo history.