I had the same problem but in my case it way a blue tile on 10/7
I managed to find my problem using this guide:
It's sorted after dates so you can see which date belongs to which tile and to which person.
I found out that save 4 (x360a guide) is save 9 in the one above and save 5 is save 15.
In my case I missed a bad ending...what a stupid mistake >_>