Have you tried to configure the cloud save? That's the only thing that could modify save files.
Viewing post in Bug report
Yes I have cloud save. In fact, I signed out, keep Save 1 (still has my name), delete Save 2 and Save 3 (last saved about 10h ago), both with someone else's name), quit the app, open and sign in again, and it re-downloads Save 2 & 3. It kinda feels like as if my saves are mixed up with someone else's......
It's good that my Save 1 is still there, I just don't know if I can safely delete cloud save 2 & cloud save 3, cause that might be someone else's