Item bug

Ok so my Leblanc had theif's gloves(2 sparing gloves combo). And then what happen was it was a tier 1 Leblanc, I had another tier 1 Leblanc waiting and we went into a picking champions out of the pool of champions in a circle phase and I picked up a Leblanc with a sparing glove.

Now what should have happen was my Leblanc should have turned into a tier 2 Leblanc and ejected the sparing glove and kept the thief's gloves. What happen instead though is my Leblanc became a tier 2 and the sparing glove just disappeared. She kept the Thief's glove but my sparing glove just vanished.