After I set up my internet connection the password change by itself. I can see that when I click on Settings the password changed from 6 characters to 15.

A lot of password boxes will do that to help prevent people from guessing the password based on the number of asterisks or bullet points (whichever your computer uses to mask the password boxes).

That doesn't mean that it changed, it just means that it's doing that so that no one knows that you have a password with 6 characters.

Is your Internet connection just not working? Or is it working fine?