When we drag and drop reports in dashboard designer, it by default adds cache icon (blue in color) in the footer of every reports as shown in the image which you have shared. In order to remove those icons permanently you can replace below lines of code from “newwindow.css” file located at “apache-tomcat/webapp/hi-ee/css” folder.
Below lines of code is already there in the file :
Replace above code with below lines of code :
display: none !important;
Save the file and close it. Reload the dashboard and you can see that cache-footer icons will not appear in dashboard.