Where does this shadow/fold above my lip come from? How can it be improved? (Photos)

Hello everyone, I really hope someone here can help me or share some insight. I’m very unhappy with a shadow/fold that has developed above my upper lip, almost like a “dent” or a crease, and I have no idea why it’s happening. My story: In the past, I had several filler treatments that unfortunately turned out uneven and unflattering. These were later dissolved with Hyaluronidase. Since I have a lip lift, it was always challenging to find an injector experienced enough to work with my anatomy. Eventually, I went to a very expensive injector, hoping she would be highly skilled and able to enhance my lips properly. She filled my lips without touching the borders to avoid creating a duck face, and we started building my lips step by step over several months to achieve the desired shape and volume. But suddenly, this crease above my upper lip started becoming more and more visible. Now it almost looks like a “fold” or “kink” in the upper lip area. She already tried treating it with Hyaluronidase once, but unfortunately, it hasn’t improved. My question: Where does this kink/fold come from? Has anyone experienced something similar? I feel very unhappy about this situation and really hope someone here might have advice or has seen this before. Thank you so much in advance! Warm regards