Your evergreen campaign has 4 ads running, but one of them (the Founder UGC video) is driving 84% of sales. That ad works really well — but it's your only winner.
Creatives fatigue. Usually around the 45-90 day mark, performance starts to drop. When that happens, your campaign loses most of its revenue overnight because there's nothing behind it. The fix isn't to pause the hero. It's to film 3-5 variations of the same hook in the next month so you have backups ready.