Internet connection bug

This started after I began using a VPN (ExpressVPN). All other applications are able to connect to the internet. Once this alert displays, disconnecting VPN and/or resetting internet connection does not solve the problem. The only thing that seems to work is to reboot.

Has anyone else experienced this behavior? Any solution discovered?

VPNs are known to cause problems for Anki.

https://faqs.ankiweb.net/error-establishing-a-secure-connection-when-syncing.html

I don’t have any personal experience in this regard. Maybe someone else can come along who might know a way to still use a VPN along with Anki.

maybe your system still enable vpn even though you disabled vpn app
You can check proxy server in your system

I appreciate the feedback. Nevertheless, I consider it a bug. I wonder if any developer is aware.

I have no proxy server or firewall running.

Even after terminating the vpn daemon using systemd, the problem persists.

Not a single other application on my system throws an error in connecting to the internet in any way. I have confirmed full functionality of dns lookup at the command line level:

OUTPUT OF dig command:

========================
~/ dig google. com

; <<>> DiG 9.16.23 <<>> google. com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62184
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;google. com. IN A

;; ANSWER SECTION:
google. com. 119 IN A 142.250.105.113
google. com. 119 IN A 142.250.105.139
google. com. 119 IN A 142.250.105.138
google. com. 119 IN A 142.250.105.100
google. com. 119 IN A 142.250.105.101
google. com. 119 IN A 142.250.105.102

;; Query time: 16 msec
;; SERVER: 75.75.75.75#53(75.75.75.75)
;; WHEN: Fri Jan 21 06:22:23 EST 2022
;; MSG SIZE rcvd: 135

===================

OUTPUT OF ping command:

===================
~/ ping yahoo. com
PING yahoo. com(media-router-fp73.prod.media.vip.gq1.yahoo. com (2001:4998:24:120d::1:0)) 56 data bytes
64 bytes from media-router-fp73.prod.media.vip.gq1.yahoo. com (2001:4998:24:120d::1:0): icmp_seq=1 ttl=50 time=75.3 ms
64 bytes from media-router-fp73.prod.media.vip.gq1.yahoo. com (2001:4998:24:120d::1:0): icmp_seq=2 ttl=50 time=76.7 ms
64 bytes from media-router-fp73.prod.media.vip.gq1.yahoo. com (2001:4998:24:120d::1:0): icmp_seq=3 ttl=50 time=72.4 ms
64 bytes from media-router-fp73.prod.media.vip.gq1.yahoo. com (2001:4998:24:120d::1:0): icmp_seq=4 ttl=50 time=72.7 ms
64 bytes from media-router-fp73.prod.media.vip.gq1.yahoo. com (2001:4998:24:120d::1:0): icmp_seq=5 ttl=50 time=71.8 ms
64 bytes from media-router-fp73.prod.media.vip.gq1.yahoo. com (2001:4998:24:120d::1:0): icmp_seq=6 ttl=50 time=72.5 ms
^C
— yahoo. com ping statistics —
6 packets transmitted, 6 received, 0% packet loss, time 5008ms
rtt min/avg/max/mdev = 71.757/73.561/76.724/1.815 ms

======================

Some cursory Googling reveals dns - expressvpn on disconnect does not restore previous resolv.conf - Ask Ubuntu, which could possibly explain what you are seeing.