Problems!

Potassium deficiency.

I've been made aware that your grow is in Actual Dirt, and not Coco Coir, which was the basis for my suggestions. In the case of soil it's a different matter all together. If you've not mixed aeration of some soft then you will likely water log your soil and suffocate the plant and cause the roots to rot and die. All you can do is water with pH'd water.

Looking at your diary, 800 ppm is a bit low for these size of plants at this stage of the growth. Check the EC of the drain to really know what’s happening.

Never FLUSH IN SOIL, fact. Feed less, stop feeding, but dont flush soil. It doesn't look bad, put her on 2 or 3 plain water cycles, no feeding at all. She should perk up, you will have time for PK boost if it will be needed .

If you are into week 5ish of flower which it looks around there, and you've not given your soil a flush up to this point, you are likely having a potassium lockout due to excess salts in the soil and built up around your roots. I always recommend to flush at week 3 of flower to eliminate the salts that have built up during the veg period and into flower. Especially when using synthetic liquid nutrients. Flushing out your soil with 6.2 pH water with plenty of runoff out the bottom using room temperature water will reset the soil's pH to 6.2 and will ensure a smooth sail through to the finish without cooking your plants with toxic salt laden soil. Your soil pH could also play a role in nutrients becoming unavailable to the plant. Check it with a litmus paper (it's the easiest and cheapest way.) Too much calcium will lock out potassium, and vice versa. Always follow the bottles mixing rates and always maintain a 6.2 pH when you water in. As plants bloom their need for potassium goes way up. So without knowing what nutrients you are feeding it's a bit of guess work. If it were me, in your situation, i would do exactly that. Flush your soil with 6.2 pH water. Have at least a gallon of runoff out the bottoms. I do this in a bath tub. Then put your plants back in the space and wait a few days, or you can even wait till next feeding if you want to maintain a schedule (it won't hurt them to flush and not re-feed for a week) Then resume feeding at the strength recommended for the week you are in. The damage that's already done won't repair itself but, the damage will not progress any further. Don't pick off any damaged leaves unless they are 50% damaged or worse. Try to maintain a consistent environment in your space so that the plants are transpiring at the appropriate rate (VPD Matters) I hope this helps you. The information provided above is via 40 years of grow experience. I'm not a youtube taught inexperienced grower. Best of Luck! And feel free to DM me any time with any questions you have, i'm happy to help if i can.

My thoughts are same as asnoriu that it's needs more potassium or it's not taking in the potassium that's in the soil, so it could be a PH issue.

Potash

Looks like an overfeed to me buddy. thats the sypmtoms i would get if i took it heavy on the nutes. I would just reduce your nutrients slightly its not that bad and probably wont cause a lock out if you act quickley. Best of luck buddy shes looking like a nice plant anyway im sure she will be fine :) need anymore help just give me a message buddy always happy to chat about growing :)