My unions are sizing differently in studio and the player. It’s some problem about scaling but I’m not sure what is. After testing the game I noticed that in studio it looks okay but in the roblox player it doesn’t look good. This is just one of the examples. Other things have been also resized like this.
Unions can get corrupted, but I feel that the issue here is that the union might be built with one of the parts set on unanchored. Then it looks good in studio, but in playing the unanchored part will fall down or move around. I would rebuild or re-examine your union by separating and making sure each part you have used is anchored firstbefore you union them together, this might fix your issue.
It is not enough to anchor a union after it has come together.