Neosemantics 3.5.0.4 not working on Neo4j 3.5.5

I have installed Neosemantics 3.5.0.4 plugin on Neo4j 3.5.5.
Copied the jar file to the plugins directory and set the following in neo4j.conf file :
dbms.unmanaged_extension_classes=semantics.extension=/rdf

After retsarting Neo4j instance, I don't see the procedures with prefix semantics.* installed ( CALL dbms.procedures() ).

What can be the issue?

Thanks

Sudipta Bhawmik