Why when I put a valid request on api.duigco.org as demonstrated in the rules does it redirect sometimes, especially on the refresh browser but not on new requests?
I can’t reproduce a redirect. But with page rules you typically send a redirect, not prevent it. Without knowing what rules you configured, it is impossible to provide more information.
The first two rules are for valid requests to bypass cache, anything else redirects on the third rule. The Page Rules instructions say it only applies the first matching rule.