was the new nutrient solution you made stronger than before?
did you check to see if they ppm level has been dropping or raising?

if pH is dropping, and the ppm level is raising your plants are overfed

my suggestion is to run nothing but pH corrected water in your system and keep monitoring the pH, and don't add nutrients until the pH is stable and new growth has resumed

and if the nutrient mix is too hot right now at its current ppm, then needless to say don't have it that high when you re-add the nutrients after the flush

just my suggestion
hopefully someone else will post to help you out as well