Try to focus only some targeted country, age, or sex. also Try to choose country with low ads competition.
This is good for a metric too so you can see if there is any differentiation between what you are seeing before and what you are seeing with a new target, although you might have to jump campaigns if the one you are running is country specific restriction. Otherwise if you don't have restrictions your golden to at least diagnose if there is a creative problem or a more inherent problem