You probably just have a bunk chain. I've had this happen sporadically over the years and the main culprit has always been bent links, which is an inevitable possibility.

Assuming that your chain line is straight and installed properly (not too tight or loose), that noise is concurrent with something rubbing on the cog and/or chainring at a weird angle, which would mean a not perfectly straight chain link. Try testing any other chain on there for noise to confirm that.

That is the noise of friction, which means that something is not interfacing straight.