Unable to resolve fortiguard hostname

https://kb.fortinet.com/kb/viewContent.do?externalId=FD40586&sliceId=1
https://forum.fortinet.com/tm.aspx?m=107451

https://www.fortinetguru.com/2019/08/dns-fortios-6-2/
https://osh.pastora5w6.pw/fortigate-unable-to-resolve-hostname.html

https://kb.ic.uk/article/technical-note-dns-resolution-not-working-when-dns-server-configured-to-same-as-interface-ip-135.html

https://www.fortigate.es/viewtopic.php?t=2642

http://netzwerkmitherz.de/fortigate-dns-server-not-working.html
https://www.wormly.com/answers/sid/100/topicid/23
https://rajeevnegi.com/calculating-shooting-invitation/fortigate-web-filtering.html

http://dqbj.marchirossicostruzioni.it/forticlient-ssl-vpn-not-connecting.html
http://hafenschwedt.de/dns-port-53.html

http://icvl.jg2013-2017.de/ping-ipv6-google.html
http://kidssmile-g.com/detention-talasalitaan-adjudication/internal-error-fortigate.html
http://ejfs.musawitchproject.it/forticlient-vpn-not-able-to-connect.html
http://bsol.gilde-leviathan.de/ip-configuration-failed-due-to-dhcp-error-amazon-fire.html
https://criloreto.it/palo-alto-curl-api-key.html
http://ehne.nccnavigli.it/tcp-reset-from-server-fortigate.html
http://xotp.melca.it/vpn-error-811.html