Our ad cost surged 2x overnight and 4x in 24 hours . Any idea what caused this? For example: we were doing 4x roas, with 10, 000 reach today consistently. The result declined to 2x roas overnight, with just 5, 000 reach. And one day later the result declined to 1x roas, with 2, 500 reach . Nothing has changed in terms of budget and settings. Appreciate it if someone can shed some lights on this.