Outdoor grow, leaves turning yellow, spotting and dieing during flowering PLEASE help

I have an outdoor medical garden and our plants are flowering. Never had any problems with them until about 2 weeks ago . Some of our bottom and inner growth leaves are turning light green to yellow spots to some turning brown and dieing. The rest of the plants seem very healthy. We had a couple that finished already with no problems. We are still fairly new and are not sure if its a pest or heat issue. We have chem dawg, cannalope haze and SFV OG. All are a lil over 5 ft. from the bottom of the pot, we topped them so they didnt get too tall (privacy issues).

Our nutrients consist of liquid karma, tiger bloom, foxfarm bloom, bud candy, molassas and use foxfarm ocean forest soil. Each plant is in 5 gallon pots. We try to keep it PHed around 6.0

Please take a look at some of the pictures i took of some of my leaves. Any advice will be greatly appreciated! View attachment 997696View attachment 997701View attachment 997705View attachment 997702View attachment 997704View attachment 997706View attachment 997700
here's a nug from last harvest View attachment 997697

mine started doing that about 2 weeks ago as well, I came to the conclusion that they were root bound, so transplanted them into bigger pots. One is recovering really well, the brown crunchy leaves are even perky which gives me good hope. There is one though that still looks droopy, I put a knife down and made a bunch of cuts about 1/2" deep around the root ball to try and free up the roots. Hopefully she will pick herself back up, I believe its week one into flowering now so they have time to recover, and get back on track