I noticed if I have Oculous installed when switching to 3rd person, the player model and NPC models float up and to the side.
I've tried removing all my mods to figure it out.
I didn't see anything about Oculous being incompatible, so I thought I'd drop it here.

I can confirm that Oculus (version 1.7.0) is also causing this issue

With Oculus Installed, No Shader:

With Oculus Installed, with Shader (using Insanity shader for experiment):

Without Oculus Installed:

I do find it interesting though that using a shader actually fixes it.

Oh wait, I just noticed this comment above, I will check with that

Oh I'm sorry, it seems to be "hit feedback" ( https://www.curseforge.com/minecraft/mc-mods/hit-feedback/comments ) I'm sorry for wasting your time, but that also sucks, feels nice when you get a good hit feedback with a sniper.

Hit Feedback (version 1.1.3, NeoForge) disabled and Oculus (version 1.7.0, NeoForge) works, it is an issue on the other mods end

Oh weird, different shaders can cause this? Yeah that's a bummer. Thank you for your time!

Oculus works fine with tacz on my computer. We need more information to diagnose your problem

Oh I'm sorry, it seems to be "hit feedback" ( https://www.curseforge.com/minecraft/mc-mods/hit-feedback/comments )
I'm sorry for wasting your time, but that also sucks, feels nice when you get a good hit feedback with a sniper.