Amazon Fire Stick Streaming Issues with C7000v2 Nighthawk Modem/Router

[jjmarlia]

For the past few months, I have had issues streaming specific programs, particularly from Disney+ on multiple Amazon Fire Stick devices (Gen2 and 4k).  I have both devices connected through a Ethernet to USB but the issues happen when connected by WiFi as well.  I do not have issues when steaming through by laptop or when connecting the fire sticks to a mobile hotspot.

Setup:

C7000c with Spectrum controlled FW v1.02.09

Speedtest confirms 100Mbps download / 10Mbps upload

I have many smart devices connected via WiFi and use both Ethernet and WiFi throughout the home to connect devices.

Please advise on how I might T-shoot this issue further or if additional setup information is needed.

[jjmarlia]

Update: 
- Issues remain, with many programs on Disney+ still not streaming properly (while others will).

- Since my original post, I have reset my C7000c router to factory defaults (first with the doing recovery of settings and then later with accepting all factory defaults and only reseting the wi-fi SSID's. 
- Unfortunately, I cannot control the FW versions which is managed by Spectrum so I can't test an earlier release.  But I'm not finding any community postings that would implicate the FW.

- We added a new Amazon Fire TV Stick (4k) from Christmas and it, like the other two, has the same issue.

I remain at a loss as to how to debug this further.  I've not talked with support representatives yet but I'm expecting a lot of finger pointing between Spectrum, Netgear, Amazon, & Disney+.  I'd still appreciate any advice that this community might provide.  Thanks.