Problems with higer StallGenLimit (decreases ga performance)

Hey all

I want to minimize a function with 15 variables. I am using ga and, initially, I leave the default options, except for the population size = 300 * 15 (I know, a lot). The optimizer generally finds solutions in the first two generations, and it finishes after 50-55 generations.

Now, if I increase the stall generations ('StallGenLimit = 75'), the optimizer do not find solutions anymore (all the solutions = inf). I have not changed anything else. How is the StallGenLimit affecting the optimization? I thought it would only enlarge the number of generations when the tolfun would be evaluated.

Hope you can help. Thanks!

Sebastian