Many Street Map tiles not displaying in Australia and New Zealand

We have been looking into using the OSMaps service (http://129.206.228.72/cached/osm.) as a backdrop for some of our software, and have reached the initial testing stage.
Early last week (1 November 2016) I noticed that at some zoom levels, the tiles would no longer display for areas of New Zealand and Australia. I assumed this was due to an update or a temporary issue with the data server, but I am still getting the same problems.

The areas that I have discovered are ‘broken’ are around Auckland, New Zealand at zoom level 15 and closer. We also get similar issues around Melbourne, Australia. I have yet to test any other areas.

This error happens across all browsers, OS’s and computers I have access to, so it does not appear to be caused by something local.

Has anyone else experienced the same problems, and if so, is this something we can resolve, or is there a problem with the service itself?

Regards

Mathieu
OMNILINK

When I click the link you mention I get

so are you accessing opengis.net ?
Did you try to contact them ?

Basically OSM is just data, many providers install that data on their own servers and provide services around them.
I think this is one of those providers. I fear the OSM community cannot really help you, but the opengis.net people can.