Hey
So, from going through ur weeks I can see a few possibilities, also.
You need to add cal, in some way. As Plagron Nutrients you need them. I've the alga, you've terra. These are more mineral nutrients. But you need to add a cal
So, i seen in your earlier weeks you had pigment mutation. And early in your grow I seen water droplets which could of burnt the pigment from your light through the droplets and its showing itself at this points now.
Add a calmag. If you are gonna mist or foliar spray your plants be sure your light is lowered as any mineral nutrients (has salts) could of made these points weaken
So, any heavy drops wipe off. Or give ur main stem a lil shake. Try not get and Terra Nutrients on your leafs with lights on high.
But yeah, cal is key at this stage.
Also. Green Sensation, shouldn't be used now. Plants take much better to adding this stuff at the right moments. Adding too soon, when its actually needed (last 4-6 weeks) after pre flower. This could be causing an issue. As I said its not meant 2 be given during or before pre flower mate.
What you want for perflower is a stimulating nutrient like power buds (meant to help make more shoots and denser stigmata, (denser pistils). Then after pre flower the High pk is used to boost when needed. I'm not exactly saying it'll cause harm. But it'll do better given it at it's rec stage it was built for. Bud expansion (which you've no buds yet)
Feel free 2 dm me if u need help mate. Power roots you can keep giving also adding pure zym is really great for helping nutrient uptake and lowers PH around the roots intake points & helps uptake & break down any dead roots.