A certain combination of parameters leads to unexpected results about rio-cogeo HOT 9 CLOSED

$ gdalinfo --version
GDAL 3.4.0dev-8dddba9d9065bf0a2f41be1282ff2dba79c21797, released 2021/06/16

$ gdalwarp -of VRT -dstalpha original.tif out.vrt
Creating output file that is 8366P x 10042L.
Processing original.tif [1/1] : 0Using internal nodata values (e.g. 0) for image original.tif.
...10...20...30...40...50...60...70...80...90...100 - done.

$ gdal_translate -of COG -mask 4 out.vrt out.tif
Input file size is 8366, 10042
0...10...20...30...40...50...60...70...80...90...100 - done.

$ rio info out.tif | jq -c .mask_flags  
[["per_dataset"],["per_dataset"],["per_dataset"],["per_dataset"]]

$ rio cogeo create --add-mask --use-cog-driver --web-optimized \
/vsicurl/https://github.com/mapbox/rasterio/blob/master/tests/data/RGB.byte.tif\?raw\=true rasterio.tif
$ rio info rasterio.tif | jq -c .mask_flags 
[["per_dataset","alpha"],["per_dataset","alpha"],["per_dataset","alpha"],["all_valid"]]

$ rio info original.tif| jq -c .compress 
null
$ rio info cogeo1.tif | jq -c .compress   
"deflate"
$ rio info cogeo2.tif | jq -c .compress
"deflate"
$ rio info cogeo3.tif | jq -c .compress
"deflate"
$ rio info cogeo4.tif | jq -c .compress
"deflate"
$ rio info out.tif | jq -c .compress
null

$ gdalinfo original.tif
Driver: GTiff/GeoTIFF
Files: original.tif
Size is 8366, 10042
Coordinate System is:
PROJCS["WGS 84 / UTM zone 38N",
    GEOGCS["WGS 84",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.257223563,
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4326"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",45],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","32638"]]
Origin = (615076.000000000000000,3441809.000000000000000)
Pixel Size = (1.000000000000000,-1.000000000000000)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left  (  615076.000, 3441809.000) ( 46d12'24.08"E, 31d 6'16.19"N)
Lower Left  (  615076.000, 3431767.000) ( 46d12'19.96"E, 31d 0'50.06"N)
Upper Right (  623442.000, 3441809.000) ( 46d17'39.83"E, 31d 6'13.13"N)
Lower Right (  623442.000, 3431767.000) ( 46d17'35.41"E, 31d 0'47.01"N)
Center      (  619259.000, 3436788.000) ( 46d14'59.82"E, 31d 3'31.63"N)
Band 1 Block=8366x1 Type=Byte, ColorInterp=Red
  NoData Value=0
Band 2 Block=8366x1 Type=Byte, ColorInterp=Green
  NoData Value=0
Band 3 Block=8366x1 Type=Byte, ColorInterp=Blue
  NoData Value=0

$ gdalwarp -of VRT -dstalpha RGB.byte.tif RGB.byte.vrt 

$ gdal_translate -of COG -mask 4 -co TILING_SCHEME=GoogleMapsCompatible RGB.byte.vrt RGB.cog.tif

$ rio info RGB.cog.tif | jq '.mask_flags' -c 
>>> [["per_dataset","alpha"],["per_dataset","alpha"],["per_dataset","alpha"],["all_valid"]]

$ rio cogeo create --add-mask --web-optimized --use-cog-driver RGB.byte.tif rgb_cog_jpeg.tif -p jpeg            
$ rio info rgb_cog_jpeg.tif | jq '.mask_flags' -c 
[["per_dataset"],["per_dataset"],["per_dataset"]]