you can do a HTTPtrace and find out the settings required for IE mainly you need to set the IE settings check note for these 1924378 - SAP GUI for HTML: Info about standards and quirks rendering modes (731 11) Installed 1926394 - SAP GUI for HTML: Rendering mode update
note can be relevant:
#1900896 - Browser: IE Restrictions for Portal and NWBC content - IE Quirks and Standards Document Modes