New to coding for Value Areas, any advice?

Has anyone used pine script to code up multiple value areas? Been trying to automate some parts of my trading.

The results are different to the FRVP when I try to manually do it to compare results. It’s for NQ and I’ve tried coding both RTH and Globex levels but they differ to when I try to do it manually. Any advice please?

First time trying this so I’m very open to guidance