@JStyleTech:
Possibility #1 - If your caching currently works and your SSL is setup correctly, there might just be a limitation with the "Maximum object size" under the "Local Cache" Tab of Squid. If you want to cache a 100Mb file this setting should be at least "100000" as it represents kilobytes. I currently have mine set to 300000.
richie1985 allready post his squid.conf
and "maximum_object_size" is set to 512000 KB
@JStyleTech:
Possibility #2 - perhaps you have an proxy exception rule applied to either an IP address or URL which could be linked to a hosted CDN. If you don't use any proxy exception rules then you can ignore this, but
if you do you might try disabling the rule temporarily and simply retest.I've personally setup two Aliases for this specific reason "Proxy_Bypass_Hosts" and "Proxy_Bypass_Ranges". I use these specifically to whitelist sites, IP's and/or IP Ranges using ARIN and Robtex when addressing problem applications or services.
Cand find anything that point to an exeption in the squid.conf