Im sure it's been solved before but I cant seem to figure out whats happened in my case though reading other threads.
Yesterday I was baking using the Marmoset tangent space and everything was baking really clean.
Was pretty satisfied with the above results, went to clean up some final little things today and re-exported my low (coming from maya) and switched my tangent space in marmoset to Mikk / xNormal (for substance painter and UE4). Amidst trying to troubleshoot, not sure what has happened to my lowpoly, but my bake is now messed up. See artifacts below.
Artifacts, visible seams, the whole bit.
Trying to fix this I have tried exporting with and without tangents and binormals, doing a soften edge on the whole thing (hard edges on UV boarders, etc - at this point im pretty confused. I don't know if I have ruined something in the "synced workflow" or if I messed up my low somehow trying to fix bake stuff. Low is triangulated, definitely using the correct mesh.
If anyone has any advice, or thinks they know what might have happened here, I would be stoked to hear! :^) Any help is greatly appreciated!