Sudden slowdown when gaming on rpcs3

Hi, I currently play most of my games on the zephyrus g14 rtx 2060 max q version.

for instance when I Play Dragon ball z budokai for example, The game runs steady at 58-60 fps, and all of a sudden after 40 minutes it slows down to 45-48 fps. What could be the reason for it? and maybe there is a way to reduce the chances of it happening?

Thanks in advance