You search in a folder with subfolders using the "Search in current folder only" option but see more than the set amount of files to load. As you scroll to the bottom of the search results, matching search results from outside the current folder load unexpectedly. The behavior is not seen within the Advanced Search fields, as they are not using Solr search.
The Support team isolated this behavior to a defect in the Solr search functionality (Xinet-9078) in older releases of Xinet. The Development Team fixed this within the 2019.1 release of Xinet.
To resolve this trouble, reference the steps within Downloading Xinet Installers to acquire the installer and Update your Xinet Server to 2019.1 or newer.