Mangel, zuviel Dünger oder normaler Prozess

The top leaves where buds are located are not a problem. Your plant has some little deficiencies but you are going to end the flowering. If it would be my garden I would feed the plant with your fertilizer that you're using in flowering at least one or two times in 14 days. Not more because you will need to do a good flush. CalMag from biobizz is good because it doesnt have nitrogen BUT, plants need nitrogen to absorb in a better way the calcium and the magnesium. So, you can use a calmag feeding like the CalMag amino from Xpert Nutrients to solve the problem in a fast way. Let me know how it will go!