Just updated my machine to Plasma 6.3. Noticed right away an issue with Dolphin and icons.
Note the different sizes. At first I was thinking this is how hidden files/folders are shown now, but not all hidden files/folders are shown in small size. If I increase the icon size all the way to 96 pixels then all folders appear of a uniform size, or alternatively if I turn off folder content previews they all go back to the same size.