The standard behavior of RadProgressArea is to disappear once the progressing process has finished. If you want to have progress area after the uploading process has finished, you can use custom progress and set its progress indicators properly. For more information on custom progress monitoring you can use the Monitoring Custom Progress online example
and the Custom Progress Monitoring help article
I prepared an page demonstrating how you can achieve the desired functionality. Please, find the example attached and feel free to modify it so that it serves your needs.
Please, let me know if you need further assistance.
the Telerik team