Hi
I'll need to look to see if FB started suppressing image caching. AFAICR, they serve all images from a script.
WinGate 8 has cache rules in the cache module (as opposed to cache control item in flow-chart policy), which allow overriding cache-suppression from the server. It also can cache https, since it has https inspection.
If you'd like to try it, send an email to
support@wingate.com, and I can send you a link to download.
Regards
Adrien