NextDNS periodically goes down for me (Dallas/Spectrum)

About once a day, NextDNS goes down for me, and I’m unable to connect to websites or the like. Typically, if I reboot my cable modem and router, that will usually fix things. (My issue sounds very similar to the issue that’s described here.)

The most recent time that this happened, which was about an hour ago, I followed the directions from the “Report network latency issue” page, and here are my results from my macOS 10.14 Mojave machine:

$ sh -c 'sh -c "$(curl -s https://nextdns.io/diag)"'

Welcome to NextDNS network diagnostic tool.

This tool will download a small binary to capture latency and routing information
regarding the connectivity of your network with NextDNS. In order to perform a
traceroute, root permission is required. You may therefore be asked to provide
your password for sudo.

The source code of this tool is available at https://github.com/nextdns/diag

Do you want to continue? (press enter to accept)
Password:
Resolvers:  192.168.7.1
Testing IPv6 connectivity

  available: false
Fetching https://test.nextdns.io
  Fetch error: Get "https://test.nextdns.io": dial tcp: lookup test.nextdns.io on 192.168.7.1:53: read udp 192.168.7.200:64225->192.168.7.1:53: read: connection refused
Fetching PoP name for ultra low latency primary IPv4 (ipv4.dns1.nextdns.io)
Fetch error: Get "https://dns.nextdns.io/info": dial tcp: lookup ipv4.dns1.nextdns.io on 192.168.7.1:53: read udp 192.168.7.200:61442->192.168.7.1:53: i/o timeout
Fetching PoP name for ultra low latency secondary IPv4 (ipv4.dns2.nextdns.io)
Fetch error: Get "https://dns.nextdns.io/info": dial tcp: lookup ipv4.dns2.nextdns.io on 192.168.7.1:53: read udp 192.168.7.200:65340->192.168.7.1:53: i/o timeout
Fetching PoP name for anycast primary IPv4 (45.90.28.0)
  vultr-dal: 16.729ms
Fetching PoP name for anycast secondary IPv4 (45.90.30.0)
  anexia-dal: 16.689ms
Pinging PoPs
  error: Get "https://router.nextdns.io/?limit=10&stack=dual": dial tcp: lookup router.nextdns.io on 192.168.7.1:53: read udp 192.168.7.200:58746->192.168.7.1:53: i/o timeout
  Traceroute error: lookup ipv4.dns1.nextdns.io on 192.168.7.1:53: read udp 192.168.7.200:64770->192.168.7.1:53: read: connection refused
  Traceroute error: lookup ipv4.dns2.nextdns.io on 192.168.7.1:53: read udp 192.168.7.200:63073->192.168.7.1:53: i/o timeout
Traceroute for anycast primary IPv4 (45.90.28.0)
    1                   *     *     *
  error: cannot write ICMP packet: write ip 0.0.0.0->45.90.28.0: sendmsg: no route to host
Traceroute for anycast secondary IPv4 (45.90.30.0)
  error: cannot write ICMP packet: write ip 0.0.0.0->45.90.30.0: sendmsg: no route to host
Do you want to send this report? [Y/n]: Optional email in case we need additional info: Y
Post unsuccessful: status 400
{"error":"0: instance.Test requires property \"Client\"\n1: instance requires property \"SecondaryTraceroute\"\n"}

My ip address is 70.122.129.34, my router is an Eero, and my ISP is Spectrum. And if there might be any other information that you may need, I’d be happy to provide it.