This reads just like an ISP gear related issue. I don't see where it's your issue yet.
Hello at my house I have an FTTH connection . It is a new home gated community in Bradenton, FL and the ISP is Spectrum. This service is called UltraFi and it isnt available to the public its just for new communities who have Metro Development Group as the developer.
Anyway we closed on the house end of July and literally every day since weve lived here the connection drops intermittently and randomly. It comes back after like 10-15 seconds. The devices never actually lose the connection they all stay connected to the wifi network and the wired devices still show "connected" but if I were using my phone or pc for example the website I was trying to visit wouldnt load and then all of asudden it would come up.
I noticed the issue when play xbox online cause I get kicked from the game im playing in but the connection isnt actually "dropped". So I started doing ping testing on my WAN Gateway, my WAN IP, my LAN IPs on both routers on the network (R7000 my main router attached WAN to LAN to the ONT upstairs and the other downstairs is an R7000P and is just in AP Mode). and I also pinged the 1st hop from my ISP aftermy LAN IP is pinged.
During these "drops" of connection for 10-15 seconds The WAN Gateway and the hop from the ISP time out a handful of times in a row before pinging again and thats when my internet is usable again. They also have absurdly high pings too. Like 800+. The average ping for the WAN Gateway isnt bad but theres obviously an issue because this happens every day multiple times and randomly. I attached a couple pictures of a tracert and my pinging results. I called the ISP two times last week. 1st tech came and literally did nothing and tried to tell me it was just wifi interference. He was awful. So i called that same day for a new tech and he came out and said our fiber line had a small kink in it so he ran a new line for me to the house. He said at the starting point of the fiber line I was getting +11 reading but when it got to the house it was only +5. That was last Thursday. Issue is still going on. I dont know what else to do or to look at for a fix. There is clearly something wrong on the ISP side I think???? But they dont want to do anything... Should I request a new ONT? Am I just S.O.L.??????
The deviices for the connection are Arris RFOG (R-ONU) CPE (https://www.arris.com/globalassets/images/products/hero-images/cp8018_rfog_hero.png) connecting the fiber cables to the Nokia/Alcatel-Lucent ONT. Data1 port on ONT goes to the WAN of my r7000. I have my xbox one hardwired to the r7000. My house is has 5 cat6 lines ran from upstairs utility room where the ONT is through the rest of the house to wall outlets. Downstairs I have my r7000p just running in AP Mode to give stronger signal downstairs.
The traceroute was for my WAN Gateway IP.