Ansible playbook with different host sets

Hi,
I have a playbook and 2 diff host sets
One set works just fine and get required info back
Other one has a problem where at the end of the set ansible just sits there and does not return anything forever
Wander what that is and how to go about troubleshooting it.

Thank you

Have the sample of what your playbook looks and is it windows or linux remote that you are running them on?