2.9.2 is a beta so issues are bound to happen...
When you say you only see the splash screen, do you mean the circular logo on top of the desktop, or do you see the actual display, which will be the same logo but on a white background. For the latter, it's just a case of the screens being configured incorrectly in OpenLP. If you press the Escape key it should hide the display and you can open the settings and change the output display to the projector.