Why does my game keep freezing?

Why does my game keep freezing?

Greetings everyone! So, when I play Rainbow 6 Siege, my pc frrezes I have task manager open on my second monitor, and when the game freezes, my CPU usage goes down to .3%. It is frozen for about 15-20 seconds, then when I get back, it says that I have around 3000 ping? Is my CPU problem or a problem with my wifi driver? I also tried using different ram, but it didnt help.