Kelly Robinson noted the attached; you receive an error with ?debug on if you are drilled down into search results and attempt a search again.
With debug off, there is no error, however, the second search still does not work.
"Uncaught Ext.data.Store.getById(): getById called for ID that is not present in local cache"
"search for something, drill down into it, then use the search in the top nav bar to look for something else"
Did not check older NX3 or NX2 at this time.