iPad Air 2 access denied to two websites

I have an iPad Air 2 32gb that has displayed the following when I’ve tried to access the Argos and Tesco Direct websites:-

Access Denied

You don't have permission to access "http://www.argos.co.uk/" on this server.

Reference #18.8e997a5c.1517943817.8e397c

Access Denied

You don't have permission to access "http://direct.tesco.com/direct/" on this server.

Reference #18.22367a5c.1517943981.5c08932

However, my husband has a MacBook Pro that can access both sites no problem from the same router so I know it can’t be a network problem. I’ve cleared the Safari cookies and cache in settings and restarted in the hope it would fix the problem but so far nothing has worked.

version 11.2.5 (15D60)

Any help/suggestions will be gratefully received 🙂