if you have well water try a chelating shampoo. you may have mineral deposits that keep your products from working!!! I think that I answered my own question. We moved! We now have well water, TBH I think we did before but the filtration system at our condo isn't the same as what we're using now and this water is hard (not overly so) with minerals. THAT is probably what's been causing these knots more than normal!
i use a clarifying/chelating shampoo almost every wash. i have fairly hard water here.
I use Quantum from Sallys