2D objects "jiggle" when moving on the mobile phone screen. What stops this?

Hi, I’m developing a game similar to Tetris, where objects fall down the screen. It’s a mobile game. My blocks spawn at the top of the screen and fall just as programmed. On my pc screen they are totally smooth as they fall, but on the android phone, they have an odd vertical “jiggle” as they fall. Is there a fix for this? I imagine it has something to do with rounding off the Y position as it falls maybe? Any help appreciated.

Would you share the code you use to make the pieces fall? Is it a significant position jiggle or like a pixel-rounding crawl? Please make sure and use code tags.