Progress not updated on XWiki 12.10.x

Steps to reproduce : create a page with the following content : 

{{job id="test" start="{{velocity}}$request.start{{/velocity}}"}}
{{groovy}}
  def logger = services.logging.getLogger('test');
  for (int i = 0; i < 100; i++) {
    Thread.sleep(500);
    logger.error('I = [{}]', i);
  }
{{/groovy}}
{{/job}}

Accessing the page with ?start=true, we'll see the job starting, however, the logs are not being displayed correctly in the page. The user needs to reload the page to see the new logs come up.

Tested on 12.10.6, 12.10.5.