Could it be that the Druid Challenge 4 is bugged? Grand Balance lasts 20 seconds, so casting 13 would take 4 mins and 20 seconds so i should get it with 13 casts and no research or am i missing part of the challenge?
Mine will keep running, I'm not sure if the latest version does it automatically, but there is a workaround on the main game page to make it always run, whether it is active same window or anything.
Thanks for the feedback, it should be fixed now! :)