"openlisters" indicates Preferences / Launching Opus / Startup / Open the Listers that were open when the program was last closed is on, and you exited and re-launched Opus, so it's brought back whatever was there before.
Try using File > New Lister to open a new copy of the Default Lister, then close any other windows except the one which was just opened.
If it still says you're using a folder format from the Default Lister, turn on Preferences / Launching Opus / Default Lister / Ignore folder format of Default Lister to prevent that from happening. (Shouldn't be needed if the Folder Formats: Quick Guide has already been followed.) Then use File > New Lister again, and that should be free from any influences except what is shown under the Preferences / Folders / Folder Formats list.