In D5 Render, we can use either Geo&Sky or HDRI to provide environmental lighting, but we can not have them both.
Thanks to @danivalus who made this scene file, aiming to keep Clouds working when using HDRI.
Also, if you think the HDRI function is blurry, then you can try this way to insert HDRI as images (change it in the Base Color Map).
OP: