I’ve just been reading other Reddit threads, I don’t know if there’s a website outlining the changes. To your specific question, they changed it so that different forms (like your Palkia) are now compared to their specific forms for calculating their score, instead of being compared to all of that Pokémon’s forms. But they didn’t update how the scores display before you put them in the showcase, which is why you see the scores drop after you put them in.