Honestly, i think you're chasing the wrong culprit.
Your creatives proved they could hold a $2 CPI before the May outage. That tells me the product and the ads were fine. the problem isn't the creative - it's the algorithm losing its damn mind after the outage.
I've seen this exact pattern with app advertisers.
One client - subscription app, $700-1,200/day spend - saw CPI go from $1.80-2.40 to $8-11 overnight after early May. the team panicked. new ABOs every day. bid caps swapped like socks. creatives refreshed weekly. targeting rebuilt on a whim.
result? Wild swings. one day $2.90 CPI, the next $9. Same CTR. same retention.
the fix? stop. Consolidate. We killed 7 fragmented campaigns down to 2 stable ones. Paused the duplication. optimised for registrations and trial starts instead of just raw installs.
Within three weeks, CPI settled back to $2.40-3.10. and retention quality jumped nearly 28%. because Meta stopped chasing cheap, low-intent installs.
So my real question: are you only optimising for installs? or feeding Meta deeper events - registrations, purchases, subscriptions? That's where the stability lives.
Stop restructuring. Let the algorithm breathe