I think it was probably a pool overload or ddos attack as some gpu miners also reported loss in hash rate about at the same time. Probably a good idea to spear the hash between luxor(gulp), f2pool(double gulp) and siamining

I tried Luxor and the same thing was happening.
@VoskCoin
I don't have any sources. But it looked like they were doing something weird
I can confirm that... It looks like they were attempted something and it was coordinated...