Germany/FRA servers faulty

Same with UK servers. The ping to the servers is normal but the resolve times range from normal to >5 seconds, which is entirely unacceptable. What's going on?

something strange is happening indeed. Here is the nexdns client log on my router the last minutes:

Apr 1 18:20:07 ubnt nextdns[1515]: Switching endpoint: https://dns.nextdns.io.#152.89.161.16,194.68.44.36
Apr 1 18:20:25 ubnt nextdns[1515]: Switching endpoint: https://dns.nextdns.io.#194.68.44.36,152.89.161.16
Apr 1 18:20:57 ubnt nextdns[1515]: Switching endpoint: https://dns.nextdns.io.#152.89.161.16,194.68.44.36
Apr 1 18:21:49 ubnt nextdns[1515]: Switching endpoint: https://dns.nextdns.io.#185.40.106.78

switches endpoint constantly and the performance is indeed at times bad

Same here on zepto-lon-1 server, requests take between 2 and 8 seconds to resolve...

This is what I was getting before I gave up, killed NextDNS CLI and restarted my backup AdGuard Home. Some things were resolving, but it was very intermittent.

Apr 01 18:41:16 nas.***.uk systemd[1]: Started NextDNS DNS53 to DoH proxy..
Apr 01 18:41:16 nas.***.uk nextdns[1438822]: Starting NextDNS 1.11.0/linux on :53
Apr 01 18:41:16 nas.***.uk nextdns[1438822]: Listening on TCP/:53
Apr 01 18:41:16 nas.***.uk nextdns[1438822]: Listening on UDP/:53
Apr 01 18:41:31 nas.***.uk nextdns[1438822]: Connected 45.90.28.0:443 (con=15ms tls=18ms, TLS13)
Apr 01 18:41:31 nas.***.uk nextdns[1438822]: Switching endpoint: https://dns.nextdns.io.#45.90.28.0,2a07:a8c0::
Apr 01 18:41:33 nas.***.uk nextdns[1438822]: Connected [2a07:a8c1::]:443 (con=15ms tls=98ms, TLS13)
Apr 01 18:41:33 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:a5e6:90c:c1c2:34e9 UDP AAAA ipv4only.arpa. (qry=31/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:34 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:a5e6:90c:c1c2:34e9 UDP AAAA ipv4only.arpa. (qry=31/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:36 nas.***.uk nextdns[1438822]: Query 10.10.10.90 UDP AAAA ipv4only.arpa. (qry=31/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:37 nas.***.uk nextdns[1438822]: Query 10.10.10.90 UDP AAAA ipv4only.arpa. (qry=31/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:39 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:f96f:b1dc:512d:950d UDP 65 itunes.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:39 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:f96f:b1dc:512d:950d UDP AAAA itunes.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:39 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:f96f:b1dc:512d:950d UDP A itunes.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:39 nas.***.uk nextdns[1438822]: Query 10.10.10.69 UDP A gs-loc.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:40 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:f96f:b1dc:512d:950d UDP 65 itunes.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:40 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:f96f:b1dc:512d:950d UDP AAAA itunes.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:40 nas.***.uk nextdns[1438822]: Query 2001:***:****:****:f96f:b1dc:512d:950d UDP A itunes.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:41:40 nas.***.uk nextdns[1438822]: Query 10.10.10.69 UDP A gs-loc.apple.com. (qry=34/res=12) 5000ms : doh resolve: context deadline exceeded

[tons of similar entries snipped]

Apr 01 18:48:35 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP AAAA www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:35 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP A www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:35 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP 65 www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:36 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP A www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:36 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP 65 www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:36 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP AAAA www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:37 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP AAAA skypedataprdcolwus00.cloudapp.net. (qry=51/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:37 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP A skypedataprdcolwus00.cloudapp.net. (qry=51/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:37 nas.***.** nextdns[1438822]: Query 2001:***:****:****:a513:8a6e:f88a:17f3 UDP 65 skypedataprdcolwus00.cloudapp.net. (qry=51/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:38 nas.***.** nextdns[1438822]: Query ::1 UDP AAAA registry-1.docker.io. (qry=49/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:38 nas.***.** nextdns[1438822]: Query ::1 UDP A registry-1.docker.io. (qry=49/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:38 nas.***.** nextdns[1438822]: Query 10.10.10.1 UDP A connectivitycheck.gstatic.com. (qry=47/res=12) cached HTTP/2.0: doh resolve: context deadline exceeded
Apr 01 18:48:38 nas.***.** nextdns[1438822]: Query 10.10.10.1 UDP A mtalk.google.com. (qry=34/res=12) cached HTTP/2.0: doh resolve: context deadline exceeded
Apr 01 18:48:38 nas.***.** nextdns[1438822]: Query 10.10.10.100 UDP 65 www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:38 nas.***.** nextdns[1438822]: Query 10.10.10.100 UDP A www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:48:38 nas.***.** nextdns[1438822]: Query 10.10.10.100 UDP AAAA www.googleapis.com. (qry=36/res=12) 5000ms : doh resolve: context deadline exceeded
Apr 01 18:49:08 nas.***.** systemd[1]: Stopping NextDNS DNS53 to DoH proxy....
Apr 01 18:49:08 nas.***.** systemd[1]: nextdns.service: Succeeded.
Apr 01 18:49:08 nas.***.** systemd[1]: Stopped NextDNS DNS53 to DoH proxy..***.**