I heard a rumor that higher perception acutally makes it harder to catch the fish. Since perception essentially makes the fish "bigger" it could have something to do with it. Something to keep in mind. I caught all 3 Olghi within 2 heatwaves at 348 Gather 250 Perception using the i55 Rod. It may be worth while to re-purchase the AF rod from the calamity salvager for farming purposes and save the Supra for the 379 Frilled Shark and other Big Fish.