It will be fine, now you can dial in your feed with out the ph and excess salts in the growing medium. Good to have a service every now and again. Week or two shall have some happier looking plants. Flushing also wets up those dry pockets that accumilate with soil drying out over and over again.
PHed 6.4 would lower your PH. You said it was 7.1 which makes some nutes not as readily avalable to the plant. Flush 2 times the pot comtainer as you said with 1/4 nute solution. Gradually increase over time. Potassium seams to be the nute locked out mainly.
After looking at you pics i can see nute lockout. You need to flush with a very weak nute solution and next time you water increase the nute accordingly. It all come good
I don't personaly ph as im a soil grower. Its a complication that soil growers can avoid. If your planning on PHing then aim for 6.5. Really there's no need for you to do so. Looking good bro, don't complicate it for yourself!
PEACE
Hashplant is the typical cannabis sativa von afganica genus. As nevilles haze is the typicle cannabis sativa von sativa genus. Then ya got indica and rudaralis. Ya get the idea
Definitely afganica. Beautiful plants though. Not all indicas and afganicas are fully body stone. Has a lot to do with harvest time as well. Only thing it wont do is create a souring high and mild psycadelic experience.