Autosave Overwriting Other Saves / Recover Saves

I went into a lot today that I know in the last month to 6 weeks, I have done extensive renovations on. The renovations were not there. So I thought ok, maybe the game crashed / didn't save, something must've happened I'll go back through my recover saves, auto saves, and my own backup save of that game.

None of these saves had a version with the lot with renovations, which I was finding very odd as I know I saved it. I then noticed a family whose last name I changed the spelling of just yesterday, was showing up in the recovered saves (from over a month ago) with the new spelling? I then went though every recover save of both my current save and the backup (copy) save of this game and THEY ALL had the family with the new spelling? The 2 specific save games have different sane file names (one being Slot_00000014.save and the other being Slot_00000015.save) yet they now appear to be identical? I am wondering if the new auto save feature is autosaving over all the save files?