I am not very sure whether this is a bug or not. We saved module configuration in two locations.
1. Module.config. this is where the original module setting parameters/values.
2. CMS database. When a module added to a page, we will save the actual selected value of module parameters with that page.
In the page admin panel, the values come from both locations. We combine and present them. In the Module DLL, the value must come from Database.
In your situation, supposed that the "module.config" has 2 parameters, now you add a third parameters. This parameter is at module.config but not presented in the Database unless you open the Page Module setting and Save it again.
This is the logic of now, and your description match this design.
I am not sure whether this should be considered as a bug or not. but we will keep this in mind in the next version.
Regards,
Jifeng Huang
Kooboo Team
Microsoft ASP.NET MVP