this issue happened to me as well. some changed made in the inventory have triggered these issues. there is one regarding the inventory that is almost alike.
Saving ungrouped Models to the Inventory saves them as one random part of the selected parts.
I looked if a bug report post was done for this but no luck, haven’t found anything
A workaround is saving them grouped, but i don’t want that, i need saving stuff to my inventory ungrouped for some reasons that has to do with my game.
If you could help me fill a ticket with this issue please it would be very helpful