In this second picture, the displayed selection box isn’t as expected. Here, it’s expected for the selection box to be exactly the same as the one in the first picture.
Okay, so it seems to have something to do with AnchorPoint. I remember having this issue in the past. To summarize, setting the AnchorPoint from Vector2.new(0, 0.5) to Vector2.zero (and naturally changing the Position) fixes it.
Not sure what’s the reason behind that… But whatever… I strongly dislike working on user interfaces for that sort of behavior. An explanation would be more than welcomed as I still can’t justify that behavior.