Simulated annealing for optimization error msg

I would like to apply SA but I get the error msg with Optimization terminated: change in best function value less than options.FunctionTolerance.

p0=[0.5 0.5];
lb = [0 1];
ub = [0 1];
ObjectiveFunction = @sumrate;
rng default % For reproducibility
[p,fval,exitFlag,output] = simulannealbnd(ObjectiveFunction,p0,lb,ub);

Below is obj function

function r=sumrate(p)
bw = 20e6;   %total bandwidth
p1=p(1);
p2=p(2);
sigma=noise(bw);
r=par.bw*( log2(1+p1*par.g(1)/(p2*par.g(2)+sigma))+log2(p2*par.g(2)/sigma) );

end

By the way, I also want to know how to set the constraint in the SA. Since the allocation for p1 and p2 should sum to 1.

And also have some Quality of service constraint for each users after calculating the optimal power from SA.

Thank you so much in advance.

MT