random picker reset

I've been using my random picker but today the dice icons were still on from the previous time I had that class (which I actually liked). But then when everyone had been chosen, I couldn't find a way to reset it or start over. It just started calling today's choices over again. I tried switching to another class and back. I also tried exiting all the way out of the program and back in, but still all students had the dice icon.

Seating plan > Tools (Spanner, top bar) > Clear dice history