I converted a Classic custom app to Lighting. The app is loaded using the Lightning Utility Bar with Open CTI Softphone properties. The app appears to work, but the Lightning Dots Spinner is overlayed on top of the UI. How can I disable and hide the spinner?

I converted a Classic custom app to Lighting. The app is loaded using the Lightning Utility Bar with Open CTI Softphone properties. The app appears to work, but the Lightning Dots Spinner is overlayed on top of the UI. How can I disable and hide the spinner?