Same issue on android. Get to a certain point in the game and it gets stuck in a loop of autosaving but never actually saving the game. You can keep playing through it. But it will never save so you'd just be wasting your time.
I played in on my note 9(8g ram version) and it happened around 60% completion of the map. Stopped playing after that because it had happened multiple times before and was tired of wasting time. Now it has happened again around 70% completion and I probably wont play anymore now to save my time. Shame, because it's a great game.