What if the rubik's cube was actually also a trap made for intruders?
It could be put inside a weaker barrier, making it an easy target for thieves, and it's easy to activate it by accident (and it's even put in a way that makes you want to fix it, since it's almost completed)
Also, the fact that there's is a riddle who asks for two specific elements makes me think that it's also a way to make sure most thieves wouldn't be able to get away (except if they were two people, somehow didn't get separated, and have the good elements)
I probably think too much about it tho