Ok so I’ve been having this problem for god knows how long now and there doesn’t seem to be any workaround. Basically I’ve got two arena legendary xp boosts that I can neither sell nor seem to work when I use them in a match (I’ll check the end game screen and I won’t of gotten any additional xp from the boost and then it just reappears in the requisition tab). None of my other req cards have this issue and I was wondering if anyone here has been having the same problem or knows of a way to fix it, thanks!
That is a glitch. Happened to me. You really don’t have them anymore, but they show and are selectable in your inventory. It just cleared out one day, out of the blue for me. Imagine it will do the same for you some day.