Yes this definitely looks like nutrient lockout from PH issues. It’s causing multiple problems to get to this stage. Unfortunately you are pretty far along for a heavy flush but I would definitely get those nutrients down.
Check run off for PH and PPM. If it’s coming out 1400 plus then you have issues and should flush some but it will risk yield.
Best of luck and happy growing.
Keep PH 6.2 to 6.8 for soil.