Smoothing issue with static meshes from Blender - Rendering - Epic

I have been searching online for over a day and trying a heap of different settings and fixes to solve this issue, but unfortunately my lack of understanding/knowledge about smoothing/normals must be giving me trouble. There seems to be plenty of posts about similar issues but nothing seems to be a fix for me. I have made a high poly sculpt of a large rock, followed by a retopo into lower poly ready for UE4. I then export the low poly from blender as an FBX with the model set to smooth shading

Unreal Smoothing Group Error (30 Second FIX!)

Smoothing — Blender Manual

The Future of Character Animation — Developer Blog

How to export from Blender to Unreal Engine without the smoothing

Modeling a Gargoyle for Unreal Engine

render – Oded Maoz Erell's CG Log

UE4 – Technical model visualization tips – Oded Maoz Erell's CG Log

mesh - smoothing issue with tris - Blender Stack Exchange

Why do my meshes look like this? - Rendering - Epic Developer

Shade Smooth (Mesh Smoothing) – Blender Knowledgebase

Smooth Vertices — Blender Manual

Issues with mesh smoothing in Unreal 5 - Asset Creation - Epic

VR Production Tools, Workflow, and Pipeline

How to get a smooth look like this (mesh, blender, 3D) - Quora

Smoothing Issue when Importing Mesh from Blender -> UE4 - Asset