[Script] I need some help with adding Item Scripts in Emerald

I am trying to add a field use script to an item in Emerald using this: https://www.pokecommunity.com/showpost.php?p=8316351&postcount=13

Other people seem to have success with it but I am having trouble. I am trying to have an item set or clear a flag (200) but I either get a black screen or the item is selected with no message and the cursor is locked until B is pressed, with the flag not being set or cleared. I have Phenom's routine inserted at 0xE446D0 with the script I am trying to run at 0xE44512 so the pointer is 12 45 E4 and using the Complete Item Editor I have the item (Exp. Share if that matters) Type set to Use-of-SELECT and Use set to 01 Anywhere, in the Script Item section, ScriptOffset at 08E44512, and ASM offset at 08E446D0. Is there something I am doing wrong?

The offset routine should be the 08E446D1, and not 08E446D0
Test and see if it works.

I recommend using the Gen 3 Tools. He is one of the best rom editors and ROM GBA hacks of Pokémon.

A print of the configuration of my Exp Share. I also use this same routine as yours.
Field script is offset ASM.