I had the same problem with my barneys farm tangerine dream. Same conditions as a different strain (nutes tailored for its liking) and still spotts up no matter what you do. Same with their Acapulco Gold.
However my colombian gold (popped the same time) is my strongest strain and most sought after of my patients.
everything in your environment sounds top notch. Might just be time to chalk it up to bad genetics/or just a bad bean and toss it. Id say kill off your two sativas and keep the indica's. They grow 100% differently, which is interesting to watch yes. but once you get deep into flower unless you have lights for your indicas and a different set for your sativas one of the two is going to suffer if they are under the same set of lights. I did 3/4 sativas my first grow and my White widow indica didnt give me anything becausei t was too far from the lights.