When the reward - Inventory_chest is fired the first item in your inventory always seems to be deleted. I have had this happen to me multiple times, removing some of my best tools because of it.

I will look into it

It was only ever tinkers tools that were in the first slot and coincidentally the ones to be deleted, never texted with another item in the first slot though

From what little testing I have done, I could not replicate your issue. Would you be able to give me some more information on what items were in your inventory and the items that were lost?

This happens to me, too. I'll give you more info in ts to help.

I've had this happen as well and it was a Tinker's tool in the first slot.

I can't seem to replicate this issue and from looking at the code I don't think there is any way this could be a Chance Cubes issue, I think it is more likely a Tinkers issue.

Edit: To elaborate, the Inventory_Chest reward does not treat the first slot specially in any way, it also uses a standard Minecraft/Forge function to get information about the items in the Player's inventory, if there is an issue I believe it to be Tinkers improperly handling this function.

Closing this issue as the reward has been removed for the time being.