Using multiple threads or parallelization in MINLP solvers

Hi there,
I am trying to solve an MINLP model using SBB solver in GAMS. I have already set the option threads=0, but it did not have any effect and GAMS uses a single thread during the solution process. However, during the model generation GAMS uses a few threads (say 4 threads). I have also checked other options like threads = 5, threads=10, etc. without any outcome. I wonder if it is possible to somehow force SBB to use multiple threads.

Thanks in advance for your useful answers.