White/green thing appearing in middle of bud?

This is seeds. Depending on when the plant likely threw a nanner which basically feminized itself. Stress can cause them, but really it's nature's fail safe for the plant to continue to survive and try to reproduce its next grow you know if it was in nature growing wild. You won't know the extent of how many seeds are In it till dry. It could just be the tips, or it could be everything or anything in between. So I would harvest, and dry. Then inspect it when I trim it, and see how bad it is. I would not grow the seeds it produces as they will likely hermi or shoot a nanner as well. Some strains are very finicky to any stress, and grower experience will play a good role in avoiding these issues, but still not a guarantee. You should still have some flower regardless to enjoy. So 🤞🏻 for you it is not really bad. 👍🏻🌱