Not sure that this issue has been already discussed / solved as I didn't find any thread on the following issue :

I have different custom content types, provisioned in a specific site collection. Some of them inherit from Document content type and others from Document Set Content type.

When I create a reusable workflow, whether its for the specific site or the whole site collection, Nintex allows me to bind my reusable workflow to a specific content type.

The problem is that I can choose from some of my custom content types, but some don't appear in the choice list.

Do you have any tips to share on this ? Are there any limitations or reasons that explain why Nintex Workflow don't display all custom content types in the choice list ?

Thank you by advance.