Greenest and zonal statistic

[joytvxq]

Hi! I was trying to do the zonal statistic mean for the greenest raster image at the U.S.state level. The output only has state information; nothing shows the zonal mean.
Anyone know why? thank you!!!

The output is this
zonal_stats.csv

import ee
import geemap
import os

Map = geemap.Map()
countries = ee.FeatureCollection("users/giswqs/public/countries")
Map.addLayer(countries, {}, "countries")
roi = countries.filter(ee.Filter.eq("ISO_A3", "USA"))
Map.addLayer(roi, {}, "roi")

start_date = "2021-01-01"
end_date = "2021-12-31"

l8 = (
    ee.ImageCollection("LANDSAT/LC08/C01/T1_TOA")
    .filterBounds(roi)
    .filterDate(start_date, end_date)
)

def addNDVI(image):
    ndvi = image.normalizedDifference(["B5", "B4"]).rename("NDVI")
    return image.addBands(ndvi)

ndviCollection = l8.map(addNDVI)

greenest = ndviCollection.qualityMosaic('NDVI')

states = ee.FeatureCollection('TIGER/2018/States')

zonal_stats_result = geemap.zonal_statistics(greenest.select('NDVI'), states, scale=1000, statistics_type='MEAN')

[giswqs]

This seems an Earth Engine bug rather than geemap. If you use ee.Image.reduceRegions without geemap.zonal_stats, you get the same result.

stats = greenest.select('NDVI').reduceRegions(
    collection=countries,
    reducer=ee.Reducer.mean(),
    scale=1000
)