Issue Summary

The maintenance banner can't be displayed correctly in Confluence as example below:

This site is read-only while we complete some maintenance. You can't create or edit pages right now 

Steps to Reproduce

1. Install any Confluence 9.x version 
2. Navigate to Administration > General Configuration > Maintenance > Read-only mode > Edit
3. Click the Banner message option and click the Submit button. 
4. Navigate to the Confluence Home page, and the maintenance banner can't be displayed correctly. 

Expected Results

The maintenance banner should be displayed correctly in Confluence for every page. 

Actual Results

1. On the Confluence Home page, the maintenance banner can't be displayed correctly. 
2. The issue seems to happen on the Confluence home page and on several tabs on the home page, as below: 
   1. Confluence Home page. 
   2. All updates tab. 
   3. Popular tab. 
   4. Recently worked on tab. 
   5. Recently visited tab. 
   6. Saved for later tab. 
3. The issue does not happen in those areas:
   1. Spaces tab.
   2. People tab. 
   3. Calendars tab. 
   4. Analytics tab. 
   5. Newly created page. 

Please refer to the screen video below regarding what it looks like as an example:
affected_and_unaffected_area.mov

Workaround

We can follow the steps listed below as a workaround:

• How to add a site-wide banner

1. Go to Confluence Admin
2. Click 'Custom HTML' in the 'Look and Feel' section of the left-hand panel.
3. Click 'Edit'.
4. Add the following code to the 'At beginning of the BODY' textbox.

   <!-- Message Banner -->
   <div style="background-color: yellow; border: 2px solid red; margin: 4px; padding: 2px; font-weight: bold; text-align: center;">
   Your important message...
   </div> 

1. Click 'Save'.