Since FortiOS 6.2 DHCP and Device inventory problems

Have you ever received an answer to this?  I just upgraded to 6.2.0 and I'm running into the same problem.  I haven't found anything in the documentation to say what to do with this.  I can go under interfaces and create a reservation, but when I'm in the dhcp monitor I get the same pop up when trying to reserve an IP.

Another issue is they remove the option to delete device inventory from the GUI.  I opened a ticket and have been informed this is by design.  Please everyone speak up as this is a mistake.  I routinely review the contents of the list to spot devices that should not be on a network.  HIPAA and HiTRUST require scanning the network for foreign devices and I always start here.  I once found a bunch of IOS devices at a site with only android phones and found their wifi was set wide open and people walking by were connecting!  That list is a really helpful feature with Fortigate and not being able to purge the list of out dated entries except by using the cli cmd: diag user device clear or diag user device del <MAC address> is a terrible alternative.