Its too late in the game for heavy nitrogen feeding, thats a personal opinion and some may disagree, but it looks like sex is showing and the stretch started so I would taper away from veg feeds and switch to bloom/flower feeds. Your plant is super dark green. Meaning its already got plenty of nitrogen. My guess is maybe your ph is a bit funky or there is excessive amounts of nitrogen in your soil locking out potassium.
Along with this, you may wanna run some plain water ph'd to 6.0-6.3 for your next couple waterings or do a very light dose of flowering feed. What you're seeing is the effects of a non mobile nutrient deficiency, but that deficiency can come from an inadequate amount in the soil or it can come from ph lock out or can be locked out by improper proportions of other nutrients. Most likely those tips will not come back, watch future top growth. If you see yellowing starting at the bottom you can up the nitrogen heavy feeds by a little.
I only say cut back on the heavy nitrogen feeding because it takes a while for nitrogen toxicity to build up to levels where its dramatically effects the plants and in the span of a few weeks your nutrient balance can get really messed up if you continue to add nitrogen to the soil
I know this chart is complicated but its a pictoral diagram of the basic nutrient interactions that 99% of plants use. Solid line shows a negative interaction, so if you start at nitrogen, if theres way too much it stops uptake of potassium, while that sits immobile in the soil it will build up amd lock out calcium, once calcium starts getting locked out it snowballs fast, but you wont see visible signs other than an extremely dark plant for a while. My last grow had this exact thing happen. My biggest plant took the brunt completely nute burned everywhere, calcium deficiency spots on every square inch of the plant...by harvest time my sugar leaves had almost completely wilted and curled up into the buds. Not a great trimming experience, also some of the worst smoke ever. But that might have been my dry and cure, in fact im pretty positive it smoke quality wise it was.