Pin the tail on the deficiency

@gottagrowsometime is correct, this is certainly a potassium deficiency, and with you being in late flower the plant could be telling you she needs more potassium which is important in the flowering stage, I wouldn't say you have a lockout after checking out your diary everything seems fine except for your humidity, low is good at this stage but not that low. Lol. It should be around 40-45%. With very low humidity, the plant is drawing water from the soil at a very high rate, and if the humidity is too low, the plant is unable to draw water at an equal rate through the stomatal openings. The result is that the plants close their stomata, which slows the photosynthetic process and leads to stress, slow growth, and compromised yield.