remix mine rewards

Not sure if this is a bug or a feature! I was on level 20 of the mines doing remixed rewards and after emptying the reward chest (I got a wooden club), I clicked it to remove the chest like usual and it became a House Plant! It was like when you break a chest and it becomes a small chest, but...

Hi guys trying my luck here as didn't have good luck on this issue on Reddit I am trying to collect all the items in Stardew between 2 (realistically probably 3) saves, and trying to prepare as well as possible to minimize randomness and tedium. One pain point is the mines remixed rewards...