Gaming laptop has sudden fps drops

First of all, I have similar issue to these:

1. Does the power of battery affect the fps of a system : bladeandsoul (reddit.com)
2. Does a dead laptop battery affect fps? : bladeandsoul (reddit.com)

Ok now my issue is, I had Asus TUF Gaming A15 gaming laptop since 6 months, and it was working perfect regarding fps. I always play games plugged-in and until now. But now I am facing sudden fps drops and I don't know why. I also suspect/doubt that the battery performance became bad (I am not sure about it). Ok now does that affects fps even if my laptop is plugged-in? Also, when fps drops, the fan noise stops for 1 second and then it works again, it only happens when fps drops. The 2nd link that I posted says that the user used throttlestop, does this fix my problem? Is it safe to use it? Is my solution is to use throttlestop or there is another better solution? Again, it was working perfect, but after 6 months I suddenly faced fps drops and when I play always play plugged-in even when this problem occur. Why did my laptop suddenly faced fps drops? Is it the battery, even if my laptop is plugged-in? How to fix this issue? My laptop is only 6 months old. If throttlestop is the solution, what settings should I alter/change?