Orb of chance bug

So I just tried to use an orb of chance on a heavy belt and both the orb and base item disappeared i tried it again on a sapphire ring and same thing happened the heavy belt and ring were both white items and they both disappeared along with the orbs

This is NOT a bug. If you read what an orb of chance does : Unpredictably either upgrades a Normal item to Unique rarity or destroys it

Since you used the orb, it's gone and a little bit of bad luck destroyed both your items.