Islands not visible on opencyclemap

I discovered that some islands in lake Wanaka are not displayed correctly in the opencyclemap. Anybody knows what is going wrong here?

It looks like it and, and the transport map, from the same third party supplier, require the water to be a multipolygon, with the island cut out, but the islands are simply superimposed on the water.

There was a whole series of issues with the tagging and multipolygons. I have now made changes that should fix this and uploaded them to OSM. For some strange inexplicable reason though, I am still getting a “coastline within water” type error upon validation in JOSM, even though there clearly is no coastline tagging on any of the objects, including any of the “inner” islands (checked manually and using JOSM search functionality). I suspect though that the error is also a translation issue with my Dutch version of JOSM, I saw another bad translation already while on this.

Beware: it may take considerable time before Cyclemap updates! I have seen it take weeks before changes became visible.