Hi John
According to the documentation: https://www.ibm.com/docs/en/content-navigator/3.1.0?topic=content-simple-search
"Depending on the repository’s search capabilities, Content Navigator does a full-text search on indexed documents in a Content-Based Retrieval (CBR) enabled repository, or search for documents whose name (Document Title) start with your specified keyword if CBR is not enabled. When you search in a CBR-enabled repository, you can take advantage of the query syntax of the underlying search engine. For example, to find documents that contain “dog” but not “cat” use the query "dog NOT cat". (For more information, see Examples of text search syntax.) The results are initially sorted by rank (relevance) in descending order for full-text searches and by name in ascending order."
So according to the documentation, in the OS without CBR your results would just be based on the document title - not all the properties - and the full search syntax would not be available. I also think that you need to explicitly set the properties you want indexed with CBR which might be why they don't appear to be indexed on your CBR enabled OS.
HTH
Lisa