Background gets transparent as i save rendered image as PNG fomat from vray framebuffer

When I render in Vray Sketchup and autosave a rendered image with a sky background, the auto-saved image has a completely opaque background; however, when I save that image as a PNG from the framebuffer window, the background has alpha or is transparent.
I now want to save in PNG format with a fully opaque background and editional changes in the vray frame buffer, such as lens effect, light mix, crytomatte, etc. How can it be solved?
My autosave settings path is: Asset editor > Save Image > Image options > Alpha > No alpha (with PNG output format)