Monitor > Firewall users page will not load when using captive portal on interface

Hi I have Fortigate 500d with 5.6.2.

When captive portal without any authentication is enabled on an interface and someone clicks through the disclaimer page an Undefined user gets listed in the Monitor > Firewall Users page in the firewall. This also makes it so that page will not load it just sits with the loading icon forever.

Can anyone else verify this happens with their system as well.