Trouble with a skeletal mesh catching light improperly as it rotates.

Bit of an awkward problem to explain so i’ve made a short video to hopefully highlight it. It’s visible at 10 seconds in.

I feel it’s most likely a problem with normal maps and i’ve searched about and played with the settings a bunch trying to see if it was something obvious. Not really knowing how to describe the question probably hasn’t helped with my searching.

I’m using tangent space normal maps and tried turning the sRGB on and off for the normal map files. The models have some separate smoothing groups and the normals were baked in substance designer/ painter with the exporter set to the UE4 export.

Any help would be appreciated. Hope I haven’t left too much information out.

Updated to version 4.10.4 and stuff is now working flawlessly. Also started a fresh project, which might’ve also been what fixed it.