Is this a nute problem ? Brown spots at the top of one plant 4th week of flower

Salam BigAdy! 👋 Those girls are looking thick for Week 4! 🌳 Let's look at this through the lens of Modern Engineering 🛠️. If you have 9 plants in the exact same soil with the exact same pH, but only one is showing brown spots, and those spots are only at the top canopy, we can rule out a general nutrient burn or soil issue. The Diagnosis: This is classic Light-Induced Calcium Deficiency. The Engineering Logic: 💡 Calcium is an "immobile" nutrient. That means once the plant puts it into an old leaf, it cannot move it to a new leaf. When a specific plant (or branch) grows very close to an intense LED light, the photons force those top leaves to work in overdrive. They photosynthesize so fast that they literally suck all the available Calcium out of the water stream faster than the roots can provide it. The result? The new top leaves get these rusty/brown necrotic spots, while the lower leaves look perfectly fine! Your Action Plan: Check the Light: Is this specific plant slightly taller than the rest, or directly under the "hot spot" (center) of your LED? If so, try gently bending that main cola down (LST) or raise your light an inch or two. 📏 The Cal-Mag Boost: I agree with @JiveBear916! Give them a nice dose of Cal-Mag on your next watering. The damaged spots won't heal (they are dead tissue), but the new growth will stay green and stop spreading. 💧 Don't panic! You caught it early. Keep up the great work! 🚀 Happy Growing! 💚