Is it normal to have FPS dips when playing Disgaea PC on Steamdeck OLED?

My Disgaea PC is getting 60 fps most of the time. but I am slightly annoyed when the FPS is dropping to 45-51. Is there an optimal settings in-game or in steamdeck so I can have a consistent 60fps?

I play dead cells in my Steamdeck OLED, which is a newer game and it runs 60 fps consistently.