Google Earth Engine NDVI no value

Question

I'm using GEE for NDVI (using landsat 8) but there is many holes in my image, can someone explain me what happened? here's the code

// Function to mask clouds using the quality band of Landsat 8.
var maskL8 = function(image) {
  var qa = image.select('pixel_qa');
  /// Check that the cloud bit is off.
  // See https://landsat.usgs.gov/collectionqualityband
  var mask = qa.bitwiseAnd(1 << 5).eq(0);
  return image.updateMask(mask);
};

var filter = l8.filterDate('2021-01-01','2023-12-31').map(maskL8).median().clip(table);


var ndvi = filter.normalizedDifference(['B5','B4']);
var lst = filter.select(['B10']).subtract(273);

Map.addLayer(lst)
Map.addLayer(ndvi)
Export.image.toDrive({
  image: ndvi,
  scale: 100,
  description: 'MAXENT-NDVI',
  region: table,
  maxPixels: 1e12
});