DataTansferService.log:
Successfully queued event on HTTP/HTTPS failure for server 'ADB-ITS-02.ad.mydomain.com'.
Error sending DAV request. HTTP code 0, status ''
Download timeout has met. DTS job {95D7ABBA-59BD-46B1-BD33-6C1661A8FEDF} will quit.
GetDirectoryList_HTTP('https://ADB-ITS-02.ad.mydomain.com:443/CCMTOKENAUTH_SMS_DP_SMSPKG$/Content_cb286a91-80a3-41fd-8a61-81ca0a50fdd5.1') failed with code 0x800705b4.
Error retrieving manifest (0x800705b4).
By googling the error code I found this thread on reddit which might help you.
Edit: Also http_code 0 tells me that it is probably not able to connect to the server at all.