Dear Arijit Laha,
we have a central hub architecture (back-end -> ERP & fron-end -> Fiori )
we have kind of similar issue, we've activaded the SICF service for Article Fact Sheet, the oData Service, the role in back-end , role in front-end (all in front-end), and the enterprise search models in back end server ; but the search does not work in Fiori Launchpad.
Also, we've realized that the search option in Fiori does not show the search option for Article Fact Sheet:
Look forward for your comments,
Thanks,
Ro