Each search adds another set of markers that cannot be removed

• Searching the same station five times leaves five overlapping markers whose icons look darker and fuzzier.
• One click opens five identical popups.
• Old results remain after changing the filter and memory keeps climbing across sessions.

1. Count markers with map.eachLayer and compare with results.length.
2. Check whether each search calls map.addLayer(L.marker(...)) without clearing.
3. Check whether clearLayers runs on a group the markers were never added to.
4. Check whether stale marker references are reused after removal.

Keep one L.layerGroup().addTo(map), call clearLayers() before each render and add new markers to the group; for in-place updates reuse a marker pool with setLatLng and bindPopup.

var count = 0;
map.eachLayer(function (layer) {
  if (layer instanceof L.Marker) count++;
});
console.log('地图上的标记数', count, '结果数', results.length);

var resultLayer = L.layerGroup().addTo(map);

function renderResults(results) {
  resultLayer.clearLayers();

  results.forEach(function (r) {
    var marker = L.marker([r.lat, r.lng])
      .bindPopup(r.name + '<br>' + r.address);

    resultLayer.addLayer(marker);
  });
}

renderResults(initialResults);

• Calling map.removeLayer on a marker that was never added silently does nothing and leaves the visual duplicate.
• Trimming an index-based marker pool without removing markers from the map leaves orphans on screen.