Deficiency or light stress?

Hey there Rollex, it's hard to say because of no diary, but i'm seeing two potential issues (both quite minor at this point!) . The first issue is the burnt tips. This is not caused by a million different reasons : it's simple nutrient burn. What you want to do is decrease your NPK by a few points just to give the right amount. You dont need to flush, flushing causes stress most of the time so it will likely make things worse not better. Second issue is the discoloration on the sides of the leafs and between the veins of the leafs. This one you're right: the root cause is probably due to the light. if you have a high intensity either because of the power or in your case because of the proximity, the plant needs more micronutrients, so that's why you're seeing signs of magnesium deficiency. if you're already giving cal mag, dont change a thing, you already fixed it. There's going to be a bit of "inertia" so the problem will take a few days to stop spreading, but the plant should recover in 10 days or less. Hope this helps ! 🚀