To do this, neighbors will need to call in ideally at the same time you do to report a problem. In GPON areas Verizon should not be doing stupid things like running the OLTs off of a single Gigabit Ethernet card. Those should be running off of 3x1Gbps or 10Gbps links per PON. This ensures oversubscription occurs at a more sensible place.
FiOS is a shared resource like Cable. Unless Cable where you can have anywhere from 5 to 500 modems on a single node, FiOS PONs are split 16-64 ways depending on the area. BPON is limited to a maximum of 32 splits, sharing 622Mbps down, 133Mbps up. GPON is 64 splits maximum with 2.4Gbps down, 1.2Gbps up. Most are 32 splits or less.
What model ONT do you have? This tells us whether you're in a BPON or a GPON area, which will help us narrow down what could be causing speeds to drop so low.
Interesting. I have noticed the exact same issue here in NJ almost daily, and similarly I am getting the runaround from tech support. I have been documenting the drop in internet download speed for over a month now. Three times a "supervisor" was scheduled to call me in the evening around 9PM to supposedly troubleshoot the problem with me, but only once did I get a call. Of course, that call was at 10:30 and the speed was fine then. Similarly, I am wired directly to their router from my computer. And I am an EE who could design their network and who has designed parts of telecom systems deployed under the ocean. It would be incredibly hard for me to buy that this problem is anything but an issue with their network's ability to handle and route traffic during prime time, which of course is one of the things FiOS is supposed to be able to do better than cable. Not in my case.
I have been documenting the daily speed drops from over 80Mbps in the AM or during the day, to sometimes as low as 3Mbps at night. Verizon, please own the problem, fix it, and provide a bill credit for reduced service. In a non-net-neutral position, Verizon charges extra for faster download speeds, which I am not always getting when using my PC wired directly to your router in the evening.
As an EE how did you rule out that the trouble isn't at the other end? That is a weird statement, unless you have a lot of data that you aren't sharing with us.