Alfresco Search Services indexes PATH values from Repository using the CascadeTracker. Once the metadata and content has been indexed, some components (like the Enterprise Admin Web Console for the Enterprise version) will report that no indexation is happening. But CascadeTracker is still catching up with the Repo to get the paths indexed. This blog post will give you some tools to check the status of the PATH indexation.
In some scenarios, specially when re-indexing, is required to remove a set of transactions from SOLR core. Once performed this operation, Alfresco Search Services can be re-started and the set of transactions is re-indexed.