I am using GA for nonlinear constraint as well as for unconstrained optimization problem. For both the problem, I am getting flat nature of best fitness value in fitness function plot. The best fitness value of first generation is not changing and other individuals approach this value as generations passes. the algorithm always ends at 51 no. of generations. I am using crossoverfraction 0.9, mutation rate 0.033 (@mutationadaptfeasible), generations 100.
I tried by providing range of initial population but in that case the best value within the given population range only , becomes the best fitness value for first generation and it is continued upto 51 generations where algorithm ends as usual for me!