I tried what you advised, but none of them works. Even after I disabled the CharacterShadowShow.js, it's still causing issues. It seems like the main culprit of this come from the ARPG_Core.js.
You can get the whole same set up like me from the official DLC store. It's free.
https://store.steampowered.com/app/2287820/RPG_Maker_MZ__ARPG_plugin_set/
However, if you want just the script files. Here it is
ARPG_Core.js
CharacterShowShadow.js
Thanks for the reply.