Change MAC address format

Hi to all,

I'm configuring MAC-based dynamic VLAN assignment for a bridge mode SSID with a FortiGate 400E, firmware 6.2.3. RADIUS server is a NPS role on Microsoft Windows 2008 R2 server.

All MAC users defined into AD have xxxxxxxxxxxx format bot FortiGate sends MACs with format XX-XX-XX-XX-XX-XX.

How can I change the format on FortiGate avoiding MAC users bulk change?

Regards.