A reminder that quality on manufactured products isn't always equal.
I bought a silver cut custom series fidget cube from antsy labs because it was the only one left, and later on that weekend, found the color I really wanted on amazon. I bought it too. The amazon one arrived first, and it is perfection. I love it so much. When the silver one arrived, though, I found that the ball seems to be scraping against something. It has a scrapey sound and doesn't move as freely as the other. I attached a video, but you may need to turn up your volume to hear it.
That being said, I still recommend getting an official antsy lab fidget cube over a knockoff. I've had a knockoff for years that I rarely use because the ball hates rolling, the gears are stuck, the dial is stuck, and the switch might as well be a sonic weapon!