Hey mate.
So, I went through a few weeks in your diary.
I noticed last week the shortage started to appear in the leaves.
I suggest you add a small amount more N into your grow. Either by adding 2 solo NPK bloom feeds with fish mix twice a week. If yellowing remains unchanged and doesn't get any worse. It should be fine.
Ideally you should have a ppm pen..but being they're organics you can push a little more without risking damage fast as it's a slow affect process. So increase. Within 3-5 days you should see it slow down.. Don't expect a rapid fix with organic nutrients.
But you can either up the feeds or give an extra solo bloomand fih mix as suggested. But its having needs not met at this stage its signs that you are short already. SO UP YOUR NUTRIENTS in % of 10-15 % every few days and you should see the slow in deg..
Feel free to reach out if you need more Insight. Keep going with the bioheaven etc,,they're tip stems & bacteria for soil and loaded with mag+Micros
Good luck