It definitely sounds frustrating to deal with the Server URL field not saving your changes, especially after seeing a confirmation that your changes were saved. From what you've described, the field is initially uneditable, then becomes editable after a delay, but any changes you make don't persist after leaving and returning to the page. The attached image details and your steps make it clear that you're following the expected process, so your experience is understandable. While I don't have specific information on why this is happening, your detailed description highlights a real issue with the settings not updating as intended.