Have you updated the router to the newest firmware? I had that issue with my first 8500, but mine turned unresponsie with an amber power light on instead of white.
It updated after I installed it so I assume it is the latest firmware. Everything was great until last night for some reason. I could not get a web page to load much less Netflix. It appears to be fine today after the hard reset so I will see how it goes. What was interesting is everything was connected [ethernet, wifi, etc.] but no internet connection until I connected directly to the modem. I can't recall ever having that issue before with any other router
Before installing the firmware for the starters better erase the settings and do a firmware upgrade. Netgear yet to plan a tool on how to carry over the setting for new firmware which will ease the upgrade progess.
As the tool will automatically backup the settings and erase the setting for upgrade to be done. Even a desktop tool would be a better.
once the upgrade is complete the same tool will have to restore the setting without affecting the new firmware stability. Its upto tool which decicdes which part of setting will be applicable and which not.
Were you seeing your speeds off speed sites directly through router before issues came up? I was going through samething until I installed "bandwidth monitor" and saw what exactly was going on at the PC. On speedtest.net and DSLRepots speedtests numbers were lower than actual connection. Odd thing is that if I connect directly to modem numbers match. For the most part speed issues for this model have been posted numerous times and like you said it is kind of new so hopefully they iron out the kinks.
R8500 unresponsive with an amber power light on instead of white
It seems you had the same issue earlier like me. I bought the R8500 Dec' 2016 and was working fine unti Last month and suddenly stopped working. Tried to reset but no use. It is unresponsive with an amber power light on instead of white.
Could you pl.. let me know how did you fix this.