What paper are you using?
just as a warning/clarification - NA2 does not work as a contrast control when doing blended pt and pd. It does not affect overall contrast, just highlight exposure.
As a precaution, I'd reduce the overall ambient light in the room where you coat if you can, and I'd coat just-in-time - don't have pre-coated paper sitting around waiting to be used. This eliminates humidification as an issue in printing - the paper is still highly moist from the fresh emulsion so long as the overall room humidity remains above say 40%.
I'd also switch from adding dichromate to the developer to adding it to the emulsion, the way you would add NA2.