Can you clarify whether it does not work only if you choose 'Worklist' ?
How To: Remove Secure Enterprise Search Bar from OA HOMEPAGE (Doc ID 1291537.1)
Installing Oracle E-Business Suite Secure Enterprise Search, Release 12 (Doc ID 462377.1)
Oracle E-Business Suite Secure Enterprise Search feature is not offered with Oracle E-Business Suite Release 12.2.4 and higher.
Oracle's strategic direction is to use Oracle E-Business Suite Information Discovery to deliver search and information discovery capabilities with Oracle E-Business Suite.
It didn't worked for any selection in dropdown.