My code is as follows. I can ensure that my parameters are absolutely correct

global B

global J

global N

global N_0

global D_k

global sum_gr

global h_k_u

global h_u_b

global h_j_m_max

global h_j_e

global b_jn

p_j1 = ones(J,N);

```
cvx_begin
variable p_j(J,N) ;
expression An1(J,N) ;
expression An4(J,N) ;
expression Bn2(J,N) ;
expression obj(J,N) ;
expression obj1 ;
expression w(J,N) ;
for j = 1:J
for n =1:N
An1(j,n) = b_jn(j,n).*B.*( log( 1+(h_j_m_max(j,n).*p_j(j,n)./(B.*N_0.*b_jn(j,n))) )/log(2) );
An4(j,n) = (abs(h_j_e(j,n))^2)./(sum_gr(1,1,n)+B.*N_0.*b_jn(j,n));
Bn2(j,n) = b_jn(j,n).*B.*( An4(j,n).*p_j(j,n)./( (1+An4(j,n).*p_j1(j,n)).*log(2) ) + log(1+An4(j,n).*p_j1(j,n))/log(2) - An4(j,n).*p_j1(j,n)./((1+An4(j,n).*p_j1(j,n)).*log(2)) );
obj(j,n) = 1e-6.*(0.4.*p_j(j,n));
obj1 = sum(sum(obj,2),1);
w(j,n) = An1(j,n)-Bn2(j,n);
end
end
minimize(obj1)
subject to
p_j<1;
p_j>0.3;
cvx_end
```

The independent variable pj is solved as 0.3, and the parameter An1 is solved as a fully sparse matrix (abnormal) in cvx, while the same parameter An1 is normal outside cvx，can you tell me why？