How to eliminate the darker problem on splicing edge when scene capture cube capture on final color?

Probably not…I’ve even tried to delete the “post processing volume” from the scene and nothing changed.
The captured target shows like the above image once set the capture source to “Final Color (LDR) in RGB” or “Final Color (HDR) in linear sRGB gamut” or “Final Color (with tone curve) in linear sRGB gamut”…