Any weapons from the Modernweapons pack is not rendered correctly in the player's or npc's (from 3rd person) hand. (slightly higher than it should be) and

Along with this, in the player's inventory menu or npcs inventory (custom npcs mod) weapons shake in the hand.
Also, when crouching, the position of the weapon and exoskeleton chestplate does not change, unlike the position of the hand. The exoskeleton model also has an incorrect rendering if you crouch.
I checked the bugs with all flans mod versions (1.12.2 from beta6 to beta10) and with all mw pack versions. (also with and without another mods like custom npcs, damage indicators etc) and the bug is present in every flans mod and packages update on 1.12.2

To Reproduce

1. take any weapon in your hand
2. Look in the inventory or third-person view
3. Put on the exoskeleton chestplate and press shift

Screens






https://i.imgur.com/qOpF3fY.mp4 (gun shaking bug)
https://i.imgur.com/Yh62ohH.mp4 (exoskeleton model bug)

Versions:

• Forge: 1.12.2-forge-14.23.5.2855
• Flan's Mod: Flan's+Mod-1.12.2-5.10.0 (The last version on which I tested the bug)