Facebook Ads Campaign Suddenly Losing Performance

In my opinion do not restart everything immediately. first check if the same people are seeing your ads too much, which audience is performing better, and if any placement is wasting budget. Then make small changes.

I'd check the creatives first. If CTR is dropping and frequency is up its probably audience fatigue. Fresh creatives would be my first test.

That’s normal, I frequently create new ad content, then test and replace it - give this a try, my friend. Good luck )

I have seen this happen with Facebook ad campaigns before. I would compare frequency, CTR, and CPM from when the campaign was performing well to when the decline started.

If frequency has gone up while CTR has dropped, I would definitely suspect some level of creative or audience fatigue.

How long had the Facebook campaign been running before performance declined?
Have you tested any new creatives or audiences yet, and did you notice whether CPM or frequency changed significantly around the same time?
Also what is the offer and what is the niche?

Sounds like creative fatigue combined with audience saturation. Duplicate the campaign, swap in fresh creatives or angles, and widen your targeting slightly to reset the delivery algorithm

I had similar drops before. I usually check frequency, CTR and CPM first to see what actually changed, then test a couple fresh creatives instead of making big changes to the whole campaign.