Here is a video with step by step about how I tie Green Lantern Perdigon. Like all perdigon type of nymphs this one is sinking fast due to slim profile and because the body is coated with resin. Usually on perdigon nymphs the bead is oversized compared with the classic proportions of nymphs. That is another reason why these nymphs are sinking so fast. If you want to know more about perdigon flies here is an old article.
My advice is to use a small drop of UV Resin. At least I do not like to use the bottle dropper because the quantity of resin is too much in my opinion.. I prefer to use the needle and to apply small drops. In this way I will apply only a thin layer of resin. Otherwise the body will be too thick and will not sink as fast as I like