See this thread for more of the same issue. I found the fix to be clearing the app cache for PMS after moving the storage to user accessible.
Steps to reproduce. Factory reset the shield, then update PMS. Setup PMS and move data to user accessible internal storage. Reboot the shield and now PMS has lost all settings and needs to be setup again. See my post linked above for steps to work around the issue. After that it continues to work even after rebooting the shield and on the latest version of PMS.
