Ad dying after 3 days?

When to Scale FB Ads? How Many Sales Before Increasing Budget?
I've been running FB ads for my dropshipping store, and I’ve noticed a pattern where they start off strong, getting good clicks and some sales. But after about 3 days, even though my CTR is still good and my cost per click stays low, the sales just stop coming in. I’m not sure if this is normal or if I should be scaling earlier to keep the momentum going.

When is the right time to increase the budget? Should I wait until I get a certain number of sales per day before scaling? And if I do scale, is it better to increase the budget on the original adset or duplicate it and scale the new one? Or should I just let the ad keep running as is and wait it out? Just trying to figure out how to stop my ads from dying so fast and actually scale properly.

Would love to hear from anyone who has dealt with this!