Losing all trained common heroes that werent picked up after finishing research in hero academy

I put 120 common heroes to be trained in the academy.
I started researching common troops(level 2).
I didnt pick all my heroes, instead i clicked done when research was finished.
All my ready for pickup heroes from hero academy level 1 were lost and now it appears as if i didnt train them at all.
Why…?

Cookie Settings