Disappearing Items when Server restart

Game mode: [Online]
Problem: [Bug]
Region: [EU]

When we have stuff which is getting crafted and then the Server does a restart, all items which where used to craft are gone. Thats why so much complain about stuff which is gone.

Steps on how to reproduce issue:
1 Make Improved Steel
2. While the crafting part is going, restart the Server
3. All items which have been used for crafting are gone
4. feeling bad