As many people testing the Blueprints, we have learn by experience that after created a Blueprint any record that gets into it's transitions is gonna keep that version until it gets out of the whole Blueprint.
Any person testing must be aware of it. It's complicate until it happens. We did a Blueprint to run on all Contacts. Now we have hundreds or thousands of records into it. Delete the Blueprint is impossible until all records get out which can be impossible.
All videos and help sites about Blueprints must show a big warning message preventing about this. Any Blueprint must be the final version because it can not be changed in the records running it already. Any testing with Blueprints must be avoided.