Lockout, nutrient defeciency, normal?

nitrogen deficiency. moving from bottom-up and tip-in. if you got marijuana branded fertilizer, it often instructs too little nitrogen in flower due to urban myhths among hobbyists. some of the lower leaves do look to have a slightly different symptom progression? the ones that start along the serated tips around the outside of the leaf. that's probably not n-deficiency. Could be too much P or too little K, since it's starting at bottom, also, i'd guess too little K. Bump N and K maybe 5-10% and see what happens over the next 1-2 weeks. step in sooner, if it continues to go downhill at same pace or faster. you have soil, but at this point in grow i bet that soil is more akin to a "soilless" context. Calculate ppms of what you've been fedding. if K is way below 180-200ish, that makes it very likely to be the issue. N should probably be around 100ppm, give or take. It should be a bit lower in flower, but still need a good chunk of it. it is a building block for more things than just leaves and stem elongation (aka vegetative growth).

Might be a buildup in the soil if you are not getting any runoff with them, then causing a bit of lockout. should use a EC or PPM pen to determin the feeds concentration, table spoon mesurements are ok, but lack some details.

more like lack of potassium and maybe phosphorus too, they were hungry. if soil i would not care, you have like 2 weeks left, but if coco, you can try few feeds of PK booster. a bit toolate, buds could be denser, but i would just finish personally.