There are a few workarounds you can try to address this issue of the internal filter resetting to external every time you refresh the page:
1. Bookmark the internal knowledge search page: You can bookmark the internal knowledge search page that has the filter set to internal. This way, every time you need to search for internal knowledge, you can simply use the bookmarked page instead of the default search page.
2. Use a browser extension: You can use a browser extension like "Filtering Bookmarks" or "Bookmark Search" to save a filtered bookmark or create a bookmark with a specific filter for internal knowledge articles.
3. Create a custom search engine: You can create a custom search engine that only searches for internal knowledge articles. Most browsers allow you to create custom search engines that can be accessed through the address bar. You can use the following search query to create a custom search engine: "yourdomain.com/.../search
4. Contact your system administrator: If none of the above workarounds are feasible, you can contact your system administrator to see if they can make a configuration change to the system so that the internal filter is saved by default.
I hope one of these options will work for you and make searching for internal knowledge articles more efficient.
