High DoH resolution latency

My DoH resolution latency is consistently ~ 500 ms despite relatively low network latency and much faster standard DNS lookups. I believe this is having a very adverse affect on browser performance.  I strongly prefer the privacy DoH offers and would rather not configure my clients to use standard DNS.

Any recommendations for additional troubleshooting?

jeffl@Dell:~$ bin/trustydns-dig https://dns.nextdns.io google.com mx
;; opcode: QUERY, status: NOERROR, id: 53538
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUESTION SECTION:
;google.com.    IN       MX

;; ANSWER SECTION:
google.com. 300 IN MX 10 smtp.google.com.

;; ADDITIONAL SECTION:

;; OPT PSEUDOSECTION:
; EDNS: version 0; flags: ; udp: 1232

;; Query Time: 423ms/0s
;; Final Server: https://dns.nextdns.io
;; Tries: 1(queries) 1(servers)
;; Payload Size: 80

jeffl@Dell:~$

jeffl@Dell:~dig @45.90.28.175 www.yahoo.com

; <<>> DiG 9.18.28-1~deb12u2-Debian <<>> @45.90.28.175 www.yahoo.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 48433
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;www.yahoo.com.                 IN      A

;; ANSWER SECTION:
www.yahoo.com. 35 IN CNAME me-ycpi-cf-www.g06.yahoodns.net.
me-ycpi-cf-www.g06.yahoodns.net. 35 IN A 209.73.179.248
me-ycpi-cf-www.g06.yahoodns.net. 35 IN A 209.73.179.247

;; Query time: 20 msec
;; SERVER: 45.90.28.175#53(45.90.28.175) (UDP)
;; WHEN: Thu Dec 05 10:26:00 EST 2024
;; MSG SIZE  rcvd: 119

jeffl@Dell:~$

jeffl@Dell:~$ 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)
[sudo] password for jeffl:
Testing IPv6 connectivity
  available: false
Fetching https://test.nextdns.io
  status: ok
  client: 2600:4040:4025:a500:f4be:481f:aff7:cff0
  protocol: UDP
  dest IP:
  server: vultr-atl-1
Fetching PoP name for ultra low latency primary IPv4 (ipv4.dns1.nextdns.io)
  hetzner-iad: 8.417ms
Fetching PoP name for ultra low latency secondary IPv4 (ipv4.dns2.nextdns.io)
  zepto-iad: 32.955ms
Fetching PoP name for anycast primary IPv4 (45.90.28.0)
  vultr-atl: 22.939ms
Fetching PoP name for anycast secondary IPv4 (45.90.30.0)
  zepto-iad: 9.386ms
Pinging PoPs
  hydron-clt: 9.298ms
  hetzner-iad: 9.36ms
  anexia-mnz: 9.352ms
  anexia-ewr: 9.324ms
  zepto-xrs: 19.305ms
  zepto-iad: 21.107ms
  tier-clt: 22.799ms
  vultr-ewr: 21.104ms
  teraswitch-pit: 40.022ms
  cloudzy-pit: 59.538ms
Traceroute for ultra low latency primary IPv4 (5.161.43.197)
    1    192.168.0.1   29ms  15ms  15ms
    2     72.86.37.1    6ms   8ms   7ms
    3  100.41.24.130   17ms   4ms  14ms
    4                   *     *     *
    5                   *     *     *
    6  62.115.56.201   12ms  11ms   9ms
    7     5.161.0.82    9ms   9ms   9ms
    8                   *     *     *
    9    5.161.8.250   12ms   9ms   9ms
   10   5.161.43.197   11ms  12ms   5ms
Traceroute for ultra low latency secondary IPv4 (199.119.65.94)
    1    192.168.0.1    1ms   0ms   0ms
    2     72.86.37.1    9ms   9ms   7ms
    3  100.41.24.132   11ms  10ms   7ms
    4                   *     *     *
    5 80.239.135.178    9ms  12ms   *
    6   62.115.10.98    6ms  10ms  21ms
    7 45.134.214.101    7ms   8ms  11ms
    8  199.119.65.14    7ms   9ms  16ms
    9  199.119.65.94   13ms  10ms   9ms
Traceroute for anycast primary IPv4 (45.90.28.0)
    1    192.168.0.1    0ms   0ms   0ms
    2     72.86.37.1   21ms  14ms   5ms
    3  100.41.24.130   11ms   9ms  11ms
    4                   *     *     *
    5 80.239.135.178    9ms  11ms   *
    6 62.115.123.124   10ms   *    17ms
    7                   *     *     *
    8 62.115.138.241   20ms  21ms  28ms
    9 213.248.96.151   28ms  20ms  25ms
   10                   *     *     *
   11                   *     *     *
   12                   *     *     *
   13     45.90.28.0   24ms  17ms  20ms
Traceroute for anycast secondary IPv4 (45.90.30.0)
    1    192.168.0.1    2ms   2ms   0ms
    2     72.86.37.1   12ms   5ms  10ms
    3  100.41.24.130   13ms   7ms  17ms
    4                   *     *     *
    5 80.239.135.178    *     *    10ms
    6   62.115.10.98   17ms  10ms  19ms
    7 45.134.214.101    9ms  11ms   9ms
    8  199.119.65.14    7ms  12ms   7ms
    9     45.90.30.0   13ms   6ms  12ms
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