Drop of frames in pokémon Alpha sapphire

Hello. So, I’m playing Pokémon Alpha Sapphire, and the game runs very well on my computer, always at 30 frames per second and I don’t usually face big problems. Amazingly, the only time I experience poor performance is on the bag, and especially when using Pokeblock. This has been very annoying, since I wanted to use pokeblocks to evolve my feebas. When I open the bag it always gets ridiculously slow. Does anyone know if I could do anything to improve this performance?