Router and security

Hello all,

I’m wondering if some more technical people on the site would help me out regarding router and security.  I recently have been experiencing slow downs on my network (using a Nighthawk X6 as a router) at certain times of the day.  When playing games the ping is really bad when in the past it has been excellent. Running speedtest on another machine I find that I am getting the download speeds I have signed up for.  I used the netgear genie app and all devices on the network were accounted for. 

My question is if someone or something was hacking my router would a low speedtest be an indication?  Anyone familiar with Nmap and is it user friendly?  Thanks in advance.