Diagonal indent on forehead 2mo after botox— what happened? (Photos)

About 1.5y ago I got botox for my migraines and slight wrinkles on my forehead. About two months after the procedure I woke up and it felt like the frontalis was being pulled apart where the indent is My injector stated this was banding and should subside with more botox to freeze the overactive muscle. However nothing has helped. I’ve gotten botox again since then after letting it wear off for 10~ months, and nothing has changed. It still hurts off and on. I’m worried but can’t find an answer