Projection problem with buffer function

I use @turf/turf 6.5.0.

Features of the screenshot :

{
  type: 'Feature',
  geometry: { type: 'LineString', coordinates: Array.from({ length: 27 }, (_, i) => [20, i * 5 - 65]) },
  properties: {}
},
...Array.from({ length: 27 }, (_, i) => ({ type: 'Feature', geometry: { type: 'Point', coordinates: [0, i * 5 - 65] } as GeometryPoint, properties: {} } as GeoJsonFeature<GeometryPoint>))

When I create a 140 miles buffer with the turf buffer function, here's what happened :

(For rendering the map, I use OpenLayer 7.1.0 in projection EPSG:4326)

The buffer of each point is correct, but every time I try to buffering an other king of Geometry, such as LineString or Polygon, the buffer is not correct : it doesn't respect the projection and the distances.

Start at Turf's buffer function and reproduce the reported result with the supplied LineString, Point features, 140-mile distance, and EPSG:4326 context. Compare the LineString and Polygon outputs with the point buffers, then define done as distances and geometry respecting the intended projection, with regression coverage for the reported case.