Is there a system to obtaining roadside sticker pikmin????

I've ranted in an earlier post (which was deleted by mods) on the Bloom subreddit about missing a blue roadside sticker pikmin and after 20 seedlings they all became everything but not the one I need. A user suggested I needed a different letter for each (which I doubted because I have collected all others with just one letter too), and my doubt got verified :/ for some reason the big seedlings only become a flying sticker of any kind lol

Is there some hidden system to sticker pikmin that I have yet to figure out, is it a thing where the entire universes' constellation has to match in a certain way or is it really entirely random??

I'm aware of the step count influence, however nothing seems to work :/