The first link here is the definitive source. The remaining links are where this configuration and very similar issues have been discussed in this forum in just the last few weeks.
https://www.ibm.com/support/knowledgecenter/en/SSQL82_9.5.0/com.ibm.bigfix.doc/Platform/Config/c_https_gathering.html
I have been trying to gather two sites [patching support and enterprise security].
The server is connected to the internet through a configured proxy, and I was able to gather other sites.
However, these two sites are failing to gather, I have tried using the airgap tool to gather, and it says sites are gathered are updated with the latest versions, but nothing is changing on the console once the the response is consumed.
GatherDB.log
Unexpected exception during gather of site Patching Suppo…
Try gathering over HTTPS. BES Gather error
Something in your path is likely blocking or manipulating the downloads. Could be your firewall, your proxy, your attacker, your ISP, or your government.
Thanks @JasonWalker
Using HTTPS it is working fine now
We added registery key for HTTPS in besconfig file
Successful we gathered all content of bessupport