Dont worry too much about soil ph. Worry about water ph. Your waters ph will overwhelm the soils ph when growing in pots. In the ground water ph isnt very important but in containers its vital. Mix up a bunch of water and ph it to exactly 6.5 then flush your soil. Really drench it. After a couple hours of full runoff feed as usual and with some CalMag but always ph it to 6.5 after mixing. If in a week the new growth is still bad you have a deficiency but I would bet ph will fix it. Its almost always ph unless your 5+ weeks into flower. If ph is wrong calcium is usually the first deficiency to show as it locks out quicker.
Thank you very much sir .