Unable to change workflow for a content type

Problem/Motivation

Is not possible to change the workflow associated with a content type.

1. go to the plugin configuration you modify the simple workflow to avoid been attached to an specific content-type (ie: blogs)
2. save the form.
3. selected content-types keep unchanged.

And the same happens with a newly created content-type.

Thanks for your time,
m.

PD: do you prefer issues here or in gitHub?