Equipping Shadow Weapon and/or Shield alters the player's ASPD inconsistently

[Vaans]

Describe the bug
Equipping Shadow Weapon and/or Shield alters the player's ASPD inconsistently, this behavior changes depending on which weapon/shadow is equipped/unequipped first.
On Assassins, offhand damage is not working and EDP doesn't recognize the weapon to cast the buff.

To Reproduce
Steps to reproduce the behavior:

1. Check ASPD with no gear.
2. Equip main weapon and check new ASPD
3. Equip shadow weapon and see change in ASPD (error 1)
   3.1) If using a GX, see changes in weapon attack behavior (error 2 no double hit on katars and dual daggers)
   3.2) Attempt to use EDP and see fail to cast due to weapon (error 3)
4. Equip shadow shield and see change in ASPD (error 4)
5. Unequip and re-equip gears in different order to see more changes of ASPD.

Expected behavior
Shadow Gear should not affect ASPD nor change Weapon behavior/limit skill usage

Screenshots
https://files.catbox.moe/txjp6k.mp4

System specs (please complete the following information):

• OS: Ubuntu 24.04.1 LTS
• Hercules Version 202406000
• Mode: Renewal