Not sure if this applies....My SA chichlid eggs would turn more oval before sprouting tails. Or, if the white has spread, they may not be viable. Some of my fish, I could use a flashlight to see the glow of the eyeballs forming in the eggs before hatching, see any of that?
If you are certain its actually a male and female (not two females, sorry not familiar with rams), could the water current be too strong and washing the silt away?