System: Steam, Win 10
Situation: imp gems on the board do not explode when clicked. Clicking on the imp gems shows purple gems, as shown in the picture below. Notice that in this picture, all purple gems on the board are matched so clicking on the purple gems does not show any info.
Creating sequence: I have reproduced this situation many times. Most of the involves some combination of click on purple gems → cast ultimate and other spells quickly before the purple gem info disappears. I cannot trigger this stably. It may have something to do with timing.