3201018 - Error SCWN801 in SNOTE (Download Service)

When trying to download a note in SNOTE using Download Service method, it fails with the below error:
HTTP client: receive method failed with return cod e SY_SUBRC 1
Message No. SCWN801

• In [dev_icm] trace, a similar error to the one here below is raised when testing the download:
  [Day XXXX] WWW MMM DD HH:mm:ss:xxx YYYY
  [Day XXXX] ***LOG Q0I=> NiBufIConnect: connection pending after 5000ms: connect (10035: WSAEWOULDBLOCK: Resource temporarily unavail
  [Day XXXX] *** ERROR => NiBufIConnect: non-buffered connect pending after 5000ms (hdl 128;apps.support.sap.com:443) [nibuf.cpp    45
  [Day XXXX] *** WARNING => Connect to apps.support.sap.com:443 failed: NIECONN_REFUSED(-10) {0004ec5b} {root-id=0050569BCDBA1EDCAC9C9
  
  
• While executing a niping test with the command "niping -c -O -H /H/<saprouter@customer>/S/3299/H/<saprouter@sap>/S/3299/H/notesdownloads.sap.com -S 443" using SAProuter, it works fine:
  WWW MMM DD HH:mm:ss YYYY
  connect to server o.k.
  send 10 messages (len 1000)
  
  times
  avg     0.009 ms
  max     0.058 ms
  min     0.002 ms
  tr  106148.098 kB/s
  excluding max and min:
  av2     0.004 ms
  tr2 244140.625 kB/s
  
  
• But when performing a niping test to the direct URL does not work ("niping -c -O -H notesdownloads.sap.com -S 443"), it results in error:
  WWW MMM DD HH:mm:ss YYYY
  ***LOG Q0I=> NiPConnect2: 20.93.183.171:443: connect (10060: WSAETIMEDOUT: Connection timed out) [D:/depot/bas/753_REL/src/base/ni/nixxi.cpp 3449]
  *** ERROR => NiPConnect2: SiPeekPendConn failed for hdl 1/sock 376
  (SI_ECONN_REFUSE/10060; I4; ST; 20.93.183.171:443) [nixxi.cpp    3449]
  *** ERROR => NiTClientLoop: NiHandle (rc=-10) [nixxtst.cpp  3416]

From SAP NetWeaver 700 to higher releases.

Download, Notes, Digital Signature, Backbone, HTTP, Download Service, DSN , KBA , BC-UPG-NA , SAP Notes Assistant , Problem