In this video tutorial, I got a message from Anjalli Pawar about disabling the Submit All on the majority of slides. Not a complicated solution but I think this accomplishes what Anjalli was looking. At least I hope so. In either case, feel free to use this approach to have only one final submit button at the end of your quiz but still can move about the exam freely.
Sometimes Adobe will improve features in new versions of Adobe Captivate without listing them as a feature improvement. To my surprise, this was the case in Captivate 2017 with the submit all feature. Because I don't always use the submit all feature, I was unaware of this improvement covered in the video tutorial until now with Captivate 2019!