With which default browser are you experiencing this pain?
IE and Google both. My vault has the autofill checked. yesterday I bought another years registration to security and back up, downloaded reinstalled, tried backup copies, none of which do diddly squit.
Does the Autofill appear when you click into a field to be filled?
No nothing. but oddly I get autofill when signing in to Norton.
Have you checked to see if it is all logins in your vault, or just specific ones that do not work? If it is just a few specific sites that do not respond, it may be some change in the web site's code that Norton need to deal with differently. You can notify Norton about these sites.
You can report the site to the ID Safe team from your product.
From the Norton Toolbar in IE or Chrome, Navigate to the login page you are having problems with. Then click on Vault is Open on the Norton Toolbar. Then click on Options beside Current Site. From there click on Report an issue with this site. Then follow the directions.