Hi Jeremy, welcome to the forums.
I’m sorry to hear this issue has affected your save. There is currently no known workaround for this issue, but I have a post here which I will update if one is found - [Known Issue][PS4/XB1] Inventory and Tool Belt Reset (Multiplayer) - #3 by Docbaconface
Your experience matches with what others have seen regarding disconnects, saving and then reloading to find inventory and toolbelt glitched.
Please let me know…
- Did your guest have a toolbelt crafted when this occured? If so, what level was their tool belt at the time?
- Do you recall what was in your toolbelt when the issue occured?
While seed number is not required for that issue, I wanted to provide some further info so you will have it for future reference.
- Each save slot can hold 1 Single Player (SP) and 1 Multiplayer (MP) Save
- The cartographer for that slot applies to both SP and MP so the seed and layout are the same.
- The days survived displayed in the main menu is for the SP save. Days survived for MP can be viewed in the MP pause menu or by checking your characters watch in game.