@turf/isobands generates wrong inner circle

[linza]

I'm trying to use isobands, but sometime got incorrect result.
Example:
Cyan (985) polygon expected to be one polygon with hole, but it generated two polygons without holes.

Grid points:

Code for reproduce:

  fetch("../point.json")
      .then((res) => res.text())
      .then((text) => {
        const pointGrid = JSON.parse(text);
        const breaks = [
          965, 970, 975, 980, 985, 990, 995, 1000, 1005, 1010, 1015, 1020, 1025,
          1030, 1035, 1040,
        ];
        let result = turf.isobands(pointGrid, breaks, {
          zProperty: "value",
        });
        console.log(result);
      });

If manualy replace two polygons with one, it turns out well.

 result.features[4].geometry.coordinates = [[result.features[4].geometry.coordinates[1][0], result.features[4].geometry.coordinates[0][0]]]    

My raw data attached
point.json
isobands.json

[smallsaucepan]

Thanks for reporting this @linza. The band in question doesn't look right when separated out:

We'll take a look.