Lost progress

Hello, I just had a problem loading up UE4 this morning: some things I saved yesterday evening were not saved:
some objects are not there or not placed right, all materials are correct and the level blueprint in which I did some work is empty.

Did I not save correctly ? I hit “exit” in the first top down menu and checked everything.
Is there a way to recover something ? I feel like I just lost about two hours of work

Thanks for your time

Okay, I just reopened the level and everything seems to be there, so false alert. Still, I wonder why it didn’t load correctly the first time around.