Where did my "The Might Jax" and "Big Bad Warwick" skins go?

So around 10 months ago, my friend and I gifted each other 2 skins. The two skins I got were The Mighty Jax and Big Bad Warwick. I was really happy about the outcome of the gifts. But then recently, about a month ago, I realized that my skins disappeared. I thought it was just a minor glitch, so I left it be. But right now, my skins still haven't reappeared.

My Jax skin completely disappeared, and by that I mean you can't even see it when picking the skin, for example; a champion has four skins: 1, 2, 3, 4. When viewing the champion's skins, you notice that 3 is missing.

When I view Warwick's skins, I see Big Bad Warwick, but it says click to unlock.

For now, I'm questioning why they disappeared, but if they still don't reappear within a month or two, I will contact Riot for help.