offhand weapon only deal vanilla damage (Enchants and attribute does not add damage)

[hkkongou]

Describe the bug
offhand attack seems does not damage base on item damage enchants/attribute as main hand item. I have a diamond_sword with smite 10 and attack damage + 20 on main hand and offhand, even i place in mainhand and offhand at the same time, the attack damage from offhand only deal vanilla damage of 7.

To Reproduce
Steps to reproduce the behavior:

1. get a sword with sharpness 10
2. place in main hand, hit a mob
3. place in off hand, hit a mob

Expected behavior
deal same damage

Screenshots
video: https://www.youtube.com/watch?v=Np5Q7M36IHE

Info (please complete the following information):

• Server version: git-Paper-100 (MC: 1.20.1) (Implementing API version 1.20.1-R0.1-SNAPSHOT) (Git: f402f89)
• Client version: vanilla 1.20.1
• Plugin version: RealDualWield_1.1.36b

Additional context
Bukkit Plugins:
LoneLibs, ProtocolLib, RealDualWield