I have the same problem but not because of the security error. It seems like the host at p.kagi.com is not responding.

➜ ~ traceroute p.kagi.com
traceroute: Warning: p.kagi.com has multiple addresses; using 188.114.97.5
traceroute to cdn-kagi.com (188.114.97.5), 64 hops max, 40 byte packets
1 192.168.1.1 (192.168.1.1) 10.676 ms 4.911 ms 4.777 ms
2 192.168.144.1 (192.168.144.1) 8.207 ms 7.823 ms 7.851 ms
3 217.11.111.56 (217.11.111.56) 9.289 ms
217.11.111.80 (217.11.111.80) 8.999 ms
217.11.111.56 (217.11.111.56) 8.485 ms
4 217.11.111.32 (217.11.111.32) 16.931 ms 19.559 ms *
5 * * *
6 * * *
7 * * *
8 * * *
9 * * *
[...]
➜ ~ nc -zv -w 30 188.114.97.5 443
nc: connectx to 188.114.97.5 port 443 (tcp) failed: Operation timed out
➜ ~ curl -v "https://p.kagi.com/proxy/images?c=...."
* Host p.kagi.com:443 was resolved.
* IPv6: 2a06:98c1:3121::5, 2a06:98c1:3120::5
* IPv4: 188.114.97.5, 188.114.96.5
* Trying 188.114.97.5:443...
* Trying [2a06:98c1:3121::5]:443...
* connect to 188.114.97.5 port 443 from 192.168.1.36 port 61420 failed: Operation timed out
* Trying 188.114.96.5:443...
* connect to 2a06:98c1:3121::5 port 443 from fd87:1f69:d383:b3ef:41f:9418:9b68:7637 port 61421 failed: Operation timed out
* Trying [2a06:98c1:3120::5]:443...
* connect to 188.114.96.5 port 443 from 192.168.1.36 port 61453 failed: Operation timed out
* connect to 2a06:98c1:3120::5 port 443 from fd87:1f69:d383:b3ef:41f:9418:9b68:7637 port 61454 failed: Operation timed out
* Failed to connect to p.kagi.com port 443 after 150213 ms: Couldn't connect to server
* Closing connection
curl: (28) Failed to connect to p.kagi.com port 443 after 150213 ms: Couldn't connect to server