3789909 - ERRORINFO_MULTIPLE_HOST_HEADER returned from the target server while using absolute URI

The error message ERRORINFO_MULTIPLE_HOST_HEADER returned from the target server while using absolute URI for the connection using ICM or Web dispatcher with the parameter icm/HTTP/client/support_http2 = TRUE

For example, if absolute URI is used as GET https://<hostname>:<port>/api/PO/UPDATES

After reproducing the issue and checking the ICM trace ICM trace, the following error can be observed 

GET https://<hostname>:<port>/api/PO/UPDATES?limit=1 HTTP/1.0
Host: <hostname>:<port>
h2: (c:x/xxxxxx) - IctHttpMessage converted to HTTP/2 HEADERS frame for stream 1
h2: (c:x/xxxxxx) - Stream 1 opened
h2: (c:x/xxxxxx) - HTTP/2 sent frame HEADERS on stream 1

• ICM
• SAP Web Dispatcher  

ERRORINFO_MULTIPLE_HOST_HEADER, CL_HTTP_UTILITY=>SET_REQUEST_URI , icm/HTTP/client/support_http2 , KBA , BC-CST-IC , Internet Communication Manager , Problem