I'm having pretty much the same problem with a default landing page and I've found this post.
Is there an easy way of setting a landing page to "Reports"? I was thinking that I may need to do the same that was suggested above but I cannot figure out what should be the "trigger" Value for the UserDashboardCategory parameter. I've tried few values like CMMyReport, CMMyReport, CMReports etc. but nothing seem to work. I'm using PEGA 7.2.1.