So closing week 7 now and my 4AM are showing signs...

Hey there so if you look into the various nutrients and their optimum absorption PHs...most of them max out at around 7, 7+. So there's available nutrients but incappable of using them. I'd say flush with some ph'ed water at like 6.5 if possible and then resume your nutrient line up...see if this helps the plants and changes the runoff ph in any way. You've got some nice flower development but if that ph could get slightly lower i think thats best and would make them happiest. I feel like the input is more of a concern than the output, but i could be wrong. You could add a soil additive like aluminum sulfate, sulfur, any of the sulfate products tend to lower the soil ph. Just a thought. Happy growing and beware of faulty or slowly damaging ph pens as they don't seem to have a very long life sometimes.