Spectrum IPv6 DNS Issue - Time Warner Internet

This question is about "Spectrum IPv6 DNS Issue", with Time Warner Cable internet and apps. As of Wednesday 6/6, I am now getting IPv6 DNS servers sent down to my Spectrum modem which are superceding the regular IPv4 DNS servers I have setup in my router. I have Google's & DNS servers configured as static DNS servers in my router's config, but when I look at the status page of my router, there are 2 Spectrum DNS servers in addition to my 2 Google DNS entries. The Spectrum DNS servers are 2001:1998:f00:1::1 & 2001:1998:f00:2::1. These DNS servers aren't working right, and are causing my Amazon fire sticks to not load some apps, take a long time to load apps, take a long time to load thumbnails, etc. I've confirmed these servers are problematic by using nslookup from my laptop and get nothing but failures when attempting to use these DNS servers. When I disable IPv6 on my laptop and use Google's DNS, nslookup works fine. I cannot disable IPv6 on the fire sticks, and I cannot disable IPv6 from my Netgear C6250 router. I need these bad IPv6 DNS servers out of my network, but don't see any way to accomplish this.

Anyone else seeing an issue like this?

Spectrum IPv6 DNS Issue?