I'm facing the same issue as you and have already raised a ticket about this on january 25th: CS142142
Where were the 6.2 policies you created placed? Were they created in the "System" folder of policy management? I think I've created my policies there, but am not sure. This folder is overwritten when performing an upgrade and should not be writable.
When you check Policy management\Assignment\Machine groups, can you see your own created policies assigned to machine groups?