Weird Stocking Stuffer luck

I don't know if this is just weird luck or what but my Stocking Stuffers keep giving me permanent skins I own, except for 1 or 2. It gave me Elementalist Lux and DJ Sona, the only two ultimate skins I own. Just used a WK Azir shard yesterday and now got that as a skin permanent. Has this happened to anyone else? I'm not really mad just curious.

[sg-lux-2]