I have this same problem. I uninstalled Xposed, but it still switches back to Dalvik. Is there another app that can automatically switch to Dalvik, or did Xposed leave something behind?
EDIT: Nevermind, figured it out. It does leave stuff behind, it came to me that I had to hit an INSTALL button to install the framework, so i had to reinstall Xposed and hit an Uninstall button to uninstall the framework.