The connectivity with updates.checkpoint.com is okay, but something is wrong at the app level.
My guess is that it happens in any R80.40 for any customer in any environment.
curl_cli --cacert $CPDIR/conf/ca-bundle.crt --proxy proxy_ip:port -v -k https://updates.checkpoint.com/
* Trying proxy_ip...
* TCP_NODELAY set
* Connected to proxy_ip (proxy_ip) port (#0)
* allocate connect buffer!
* Establish HTTP proxy tunnel to updates.checkpoint.com:443
< HTTP/1.1 200 Connection established
<
* Proxy replied 200 to CONNECT request
* CONNECT phase completed!
* ALPN, offering http/1.1
* successfully set certificate verify locations:
* CAfile: /opt/CPshrd-R80.40/conf/ca-bundle.crt
CApath: none
* *** Current date is: Tue May 4 09:52:02 2021
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* err is -1, detail is 2
* CONNECT phase completed!
* CONNECT phase completed!
* *** Current date is: Tue May 4 09:52:02 2021
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.3 (IN), TLS handshake, [no content] (0):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.3 (IN), TLS handshake, [no content] (0):
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* TLSv1.3 (IN), TLS handshake, [no content] (0):
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
* TLSv1.3 (IN), TLS handshake, [no content] (0):
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.3 (OUT), TLS handshake, [no content] (0):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
* ALPN, server accepted to use http/1.1
* servercert: Activated
* servercert: CRL validation was disabled
* Server certificate:
* subject: CN=*.checkpoint.com
* start date: Dec 2 14:59:44 2020 GMT
* expire date: Jan 3 14:59:44 2022 GMT
* issuer: C=BE; O=GlobalSign nv-sa; CN=GlobalSign GCC R3 DV TLS CA 2020
* SSL certificate verify ok.
* servercert: Finished
* TLSv1.3 (OUT), TLS app data, [no content] (0):
* TLSv1.3 (IN), TLS handshake, [no content] (0):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* TLSv1.3 (IN), TLS handshake, [no content] (0):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* TLSv1.3 (IN), TLS app data, [no content] (0):
< HTTP/1.1 404 Not Found
< Content-Type: text/plain; charset=utf-8
< Content-Length: 15
< Server: awselb/2.0
< Date: Tue, 04 May 2021 08:52:02 GMT
< Connection: keep-alive
<
* Connection #0 to host proxy_ip left intact
Page not found!