@David-TP Thanks for the suggestion. I notice though that to use KidShield I would already require an active subscription to Advanced Parental Control. Unfortunately I am using the free version so don't already have access to Advance Parental Control. The free version defaults to blocking downloads (for this age group), and whilst they is appropriate in general, it appears that the Natwest Bank's childs pocket money app (Rooster Money) has been caught in the same net (I guess that it downloads data to display and this is what is being blocked).  

  @ajharvey 

ajharvey wrote

TPlink use Trend Micro's database for content filtering/categorisation. If your issue is as simple as the kids website being mis classified, you can go to Trend's website and request a manual review of the site.

Thanks for the suggestion. It's not a web site per se, it's an app (Rooster Money). The app is issued by a UK bank for children to use to track chores and pocket-money/allowance. It's a cloud based app, so my suspicion is that the parental control may be blocking it from downloading data from the cloud. Trend Micro considers the site RoosterMoney dot com to be safe (and listed as educational). But I suspect it's the parental control aspect which blocks downloads (defined as peer-to-peer sharing, online file storage and mobile device content (e.g., music & apps)) which may be the issue. I'll see whether I can get on to the beta of the KidShield, but I hope it won't be necessary long term to pay a subscription just to allow use of a pocket-money app :-)