I'm on a 100mb NBN plan from TPG and using the Asus Ac5300 router connected to the NBN box which is installed in my house. Last month my internet speed was working fine with Speedtest showing me a straight signal line but now whenever I do a speedtest it goes up to 92mb (download) then falls down all the way to 10mb, then back up and so on. I then tested a wired connection and it's giving me a solid 98mb speed when connected to the router and the modem alone so my ISP (TPG) is not at fault here. This fluctuation is making games such as overwatch unplayable since the ping is too high. The router is located about 7 meters away from my computer which uses a WNDA 3100 Adapter. If you know why this fluctuation is happening, and how I could fix it please leave it down below.
An example of my fluctuation here: http://imgur.com/a/Xiqm4
An example of my fluctuation here: http://imgur.com/a/Xiqm4