So...you check the encounter slot of the Pokemon you caught that isn't the Pokemon you wanted to catch and put it into the RNG Reporter (maybe that's where you put it in) with the Pokemon's IVs to find what frame you landed on instead of the frame that you had to land on? (Sorry if I'm incorrect)
And also...about the current challenge. I can use Pokemon that Team Rocket temporarily had, right? Not just the ones that are currently with Team Rocket?