The default macOS setting for Displays have separate Spaces will cause the menu bar to be visible on your output screens. This does not apply to SDI, NDI, or Syphon outputs. If you have checked the option for "Show Keynote & PowerPoint screens" in Preferences > Screens in ProPresenter 7 or you have unchecked the option for "Display at Top Most Window Layer" in Preferences > Display in ProPresenter 6 or earlier, you may see the toolbar.
To resolve this, open System Preferences, click on Mission Control, and then uncheck the option for Displays have separate Spaces. You will need to log out or restart your Mac to apply this change. By changing this setting, you can show other content over your ProPresenter output without needing to disable the output first.