The PSU could be a question, but it's a decent PSU. Seasonic 850W Gold, if I recall.
But only neoscrypt? Seems.. like an odd correlation!
Neoscrypt seems to work the GPU harder than any other algo with the same core/mem settings. For example, a single RX 570 I have mining Neoscrypt is pulling 420W from the wall (the PSU isn't the most efficient) while mining Ethash the power demand is closer to 340W, so 80W less (and mining Cryptonight it is even lower - around 310W).
However, a Seasonic 850W Gold PSU is supposed to be near the top in quality so that doesn't seem a likely culprit here.
I guess hunt through Windows Event Viewer for any errors/warnings.