It seems there’s a render issue with my darktable. So this is the display from darktable
and this is the exported file I got
the exported file is much much darker than displayed in darktable, I have checked the soft proof, set profile to sRGB (websafe), style (none). I re-imported the exported JPG back to darktable and there is no difference. This is the re-imported image.
I wonder why this happened and how to fix it. Thank you.