Formats can be stored in layouts. "Openlisters" is the layout automatically created and used if you have set Opus to automatically save and restore the current window state when you exit and restart it.
Restarting Opus doesn't do anything magic, but I suspect the difference is you closed all windows and then (after restarting or not) opened a default lister. That will be different to exiting & restarting with windows open and Opus configured to save them into a temporary layout.
If you modify the format in some way and then change folders, to another that uses the same format, your changes are kept. Otherwise you would have to keep re-applying the same change if you wanted to stay sorted by date (for example) while checking things in different folders. Folder Formats: Detailed Guide explains in more detail.
But the main thing is to not worry about the diagnostic information in the tooltip if it's just confusing things more. Ask here if you need help doing something, and we can interpret the diagostics for you.