ST_IsSolid returns false after using ST_MakeSolid with a closed polyhedral surface

[basilrabi]

# POSTGIS="3.0.2 2fb2a18" [EXTENSION] PGSQL="130" GEOS="3.7.1-CAPI-1.11.1 27a5e771" SFCGAL="1.3.6" PROJ="Rel. 5.2.0, September 15th, 2018" GDAL="GDAL 2.4.0, released 2018/12/14" LIBXML="2.9.4" LIBJSON="0.12.1" LIBPROTOBUF="1.3.1" WAGYU="0.4.3 (Internal)" TOPOLOGY RASTER

WITH cte AS (
    SELECT ST_MakeSolid(
        ST_Extrude(
            ST_Translate(
                ST_Force3D(
                    ST_GeomFromText('POLYGON ((-1 1,1 1,1 -1,-1 -1,-1 1))')
                ),
                0, 0, -1
            ),
            0, 0, 2
        )
    ) geom
)
SELECT
    ST_IsSolid(geom),
    ST_IsClosed(geom),
    ST_Volume(geom)
FROM cte

The code above returns false, true, 8. I could be wrong but based on my understanding in the manual, this should return true, true, 8.