关于#matlab#while条件判定的问题，如何解决？

问题遇到的现象和发生背景

matlab 2022b while循环语句为何<=无效

prob = optimproblem('ObjectiveSense','max');


x = optimvar('x',5,1,'LowerBound',0);
obj = [0.05 0.27 0.19 0.185 0.185];
M = 10000;
a = 0;
prob.Objective = obj*x ;

cost = [1 1.01 1.02 1.045 1.065];
risk = [0 0.025, 0.015, 0.055, 0.026]';
prob.Constraints.cons1 = cost*x == M ;
QQ = [];


while a <= 0.05
    prob.Constraints.cons2 = risk.*x<=a.*M;
    [sol,Q,flag,out] = solve(prob);
    QQ = [QQ , Q];
    a = a+0.001;
end

A = 0:0.001:0.05;
plot (A,QQ,'x')