I'm sorry to hear you're having troubles moving a PM in your PM folders. Have you tried everything here:

Do You Have a Technical Issue or Question? READ THIS FIRST

Have you tried it with a different web browser?

Nothing's changed on the site and we've confirmed the move PM functionality works across a range of web browsers. Without knowing more information about what you're experiencing or the browser you're using, etc., I'm sorry I can't provide more help on this issue.