Is there a way to fix this problem with UICorner or use something else?

So I have this cooldown thing but when the size decrease the shape of the frame changes too, is there a way to fix this?

Perhaps you could use a Frame as the button’s parent, have that Frame’s ClipsDescendants on, and animate that object. The Button’s Y size mustn’t be changing with the Frame (e.g. uses Offset instead of Scale), so that the Button’s corners wouldn’t change as well.