You are using a local / in-house application which is sending HTTP request to URL and getting a certificate revocation error. The actual URL is already being bypassed both on the PAC file and the CSP/squid.conf.
"Revocation information for the security certificate for this site is not available. Do you want to proceed? Yes \ No \ View Certificate."
Accessing the URL via browser works fine and it is not possible to replicate the issue. Hence, the CRL check does not complete only when HTTP request is sent by the application.
As a workaround/solution, you may bypass the URL of the Certificate Authority where the CRL check is made.
1. Identify the CA by clicking on View Certificate ( e.g. Comodo )