Have had similar problem - Honor Oak Road, Fairlawn School end of the road.

Over the last 2 months there have been at least 4 or more occasions when we have not had post for 3 days or more and then it all arrives i.e. bundle of letters together as compared to one or two letters every day. The most recent period when we got no letters for 4 days was between 11th and 14th May & then 8 letters arrived on the 15th May.

I would say there has definitely been a problem over the last 2 months.