Remember:
FMC & OPT will give most accurate stab trim when CG is entered in TO page, having selected Flaps, Thrust and Derate.
AFM & QRH & FPPM have reference tables which adjust "uncorrected" trim to stab trim based on flap and thrust setting only. In these tables there is no disparity between e.g. Flap 1 & 5, which if selected on FMC does generate a change. Thus these tables are simplified.
Best way to fly the 737 in trim: use OPT or FMC in combination with actual CG for takeoff as per loadsheet.
Always a little out of trim when using simplified referenced figures.