Thanks for getting back to me. I have now booked in the appointment for the day & time specified in my PM'd reply. Please let us know how the visit goes. If the engineer is unable to find anything amiss I shall take another look with a view to raising up to networks. If I'm away when you post an update one of my colleagues can take over for me until I return.
I set up a thinkbroadband graph. The point where the constant red ends is where I went into the router settings and turned off Port Scan Detection and IP Flood Detection and also turned on WAN Ping Respond