While attempting to use an Amethyst on a Crystal Orb the add Affix Menu became Unresponsive. After tapping options for around a minute I switched to Droid home and tried again. No luck. I’ve force quit the game and lost (now) two Amethysts trying to get it to work!
When the menu popped up I instinctively clicked the greyed out check mark instead of the text box adjacent. I will no longer have this issue as clicking the adjacent box works just fine.