I have a problem when my phone is connected wirelessly to my TL-WA901ND WAP. It concerns the APP advisor which comes with Norton Mobile Security.  The App Advisor prescans Apps on Google play before download. It's gives a security rating for the App, ie Safe. When my phone is connected to my main router or on 4G, the App works fine but when it's connected via my TL-WA901ND WAP, I get a "Network Unavailable " on the App. However , I do have an internet connection and all the rest of my Apps work.

The problem doesn't occur when my tablet is connected to the WAP.

Is there some setting on the WAP blocking the App Advisor, or could it be a setting on the phone ?