Weird artifact from the baked Normal Map in UE4

Hi!

I am working on a personal project at the moment, i know the workflow with substance painter and unreal 4. This is really not the first asset i am doing so i’m quite bugged with what is happening.

So here’s the problem. In substance, i baked my high resolution mesh on my low resolution mesh, as usual. Then it looks good! (With tomocco studio HDR)

Then i export the maps, as i usualy do, with the preset of the packed maps ORM.
But then, in unreal, it looks like this:

There some compression issue (i think)… i tried to find on the internet but nothing, even going 16 bit does not help…
The weird thing is if i remove the baked normal map, and apply a layer with a custom normal map. It works fine. Oh and there is banding if i apply a AO layer as multiply on top of everything (as i’m used to do)…

I’m quite lost…

PS: this is my first post here so, i don’t know if the images will works. I will try to adjust as the troubleshooting goes.

Thanks!