Low frame rates Alienware M15

Hi Guys, 

I have an Alienware M15 laptop and I am experiencing some low frame rates recently. I am updating my drivers/Bios as new updates are available. I play WoW and having 60+ fps at first and then they drop to a level of 10 fps. I have switched the preffered GPU to my Nvidia GTX 1070 Max-Q and still receiving the same problem. 

Does this problem sound familiar and you know how to solve this problem? Please let me know.
Thanks in advance.

Processor: 
- i7 8750H CPU @ 2.2GHz