my process or my new flour?

Hello and thank you for letting me join the discussion. Lately I have been into small baggets  as I am working on developing a easy process for making bread while on the road in our RV. As part of the process I have been modifying a basic lean high hydration recipe starting with a poolish for 12 hours (about) and then creating a dough at 70% hydration. I have been modifying the flour from 100% bread flour (+12% protein) to 85% bread flour + 15% whole wheat (KA high protien) flour. Recently I bought a bulk bag of bread flour at Sam's Club and switched when I ran out of GOld Metal (I had on hand). I am generally not a flour brand snob as long as the protein % is high enough for bread as in traveling you can not always pick your brand.

Anyway. Of late I am having issues. In dough formation I can not seem to get enough gluten formation, even with 100% bread dough. Even after 4 folding sessions over several hours and over followed with hand kneading, the dough remains a bit shaggy, tears easy and remain "wet" and sticky. I am fermenting at 68 DegF.  Is it my process or is it the flour?