Halo Campaigns Issues

Hello everyone.

Lately I’ve been experiencing some issues with the Campaigns of halo 3, 4 and ODST.
The problem is that whenever that I start a mission of any of this campaigns I have to pause the game for about 30 minutes in order to play the game without any fps massive drop (I’m talking of fps dropping from 50/60 to 1), making it unplayable during this time.
When I played halo CEA and Halo 2A I didn’t experienced any of this, but since I started playing halo 3, the problem began.
I’m currently playing it on a potato laptop, but, the interesting part is that when this 30 min on the pause menu are over, the game goes very fluid, it even gets to 50/60 fps while having explosions and vehicles