Hello Kumar,
This setting is through customization (spro setting). See these pictures.
SPRO Path
Your setting must be having this value (EMEL) in Initial funct.code field, which opens only the Header screen.
If you change this to MELD then you will get all tabs in QM01. (You will find this value if you go to the settings of QM02)
Hope this enlightens
Regards
KJogeswaraRao