Hi,

I have established a JuMP model (gurobi optimizer) and one constraint seems to be not respected:

```
@constraint(obj,OP_t == sum(sum(sum(((opex_trans[i,1,k,1]*Nsh[i,1,k,t]) + (opex_trans[i,1,k,2]*Np[i,1,k,t])) for i in 1:I) for k in 1:K) for t in 1:T))
```

with Nsh and Np two variables of shape [1:I,1:J,1:K, 1:T] and opex_trans a parameter of shape [1:I,1:J,1:K, 1:L, 1:T] and `@objective(obj, Min, CAP_p+OP_p+CAP_t+OP_t+CAP_r+OP_r)`

as objective function.

After optimization, OP_t is 0 while all parameters and variables are non null and non negative.

However, if I add a dummy variable to my model, the contraint is respected and OP_t is non null.

```
@variable(obj, 0<=dummy)
```

I do not understand how this variable that is never used â€śfix my codeâ€ť and why JuMP do not seem to respect the constraint otherwise.

Thanks in advance for your help and do not hesitate to ask for more clarification.