Metal looks different in lookdev and render I'm using the Poliigon material converter and a texture from Poliigon. 
I chose the metalness download and in lookdev it looks very good, but in the render it just looks plain and not metallic. When searching for an answer I'm pretty sure it has to do with the lighting. So I changed the HDR in render to the same studio.exr but it doesn't look any good. 
What can be done?

The top one is lookdev mode with studio HDR

The bottom on is render (Cycles, 600) with studio HDR
Cycles Render View


Cycles Lookdev View


I would say you don't use the same lightning setup for render and lookdev. Render use World and Scene Lights / Lookdev Studio light.

In the file you provided I can't confirm you use studio HDR for render, also if would use the same HDR for lookdev and  render, difference will does studio lights that are not taken into lightning in lookdev.



If I (for example) disable Studio Lights and Scene World I can see Render and Lookdev in both Cycles and Eevee matchs.