Pilz oder Hirnschmalz?

In the location with dying sugar leaves, try to gently look under the buds. Any grey or white fuzz underneath along stem?

I don’t think it’s fungus or a disease. You have no diary or give much information about your grow so it’s hard to say what’s going on here. Based solely on the pictures and information. Also because you don’t state whether it’s a photo period or an auto flower. I’m going to assume this is an auto flower plant. At 11 weeks is typically very near the end of its lifecycle and the plant is fading a bit. When there’s not enough nutrients the plant will take food from the leaves to further bud production as a last ditch effort before it dies. Just like in nature when the tree leaves start to change colour before the winter hits. To me it doesn’t look like there is much to stress about. Your buds look good and look really close to being ready for harvest. Enjoy. Take a look at my Jackie diary. She’s near the end of her life and there’s lots of fan leaves fading on her. Leaves are falling off daily. No stress. Remember buds are the prize, not fan leaves.