ASUS Dual WAN Failover Feature fixed?

Hi all

From what I seen from this link, it mentioned that under Firmware version 3.0.0.4.378.3813, dual wan fails over mode switch back issue has been fixed. I have not tested it on my RT-AC68U. But so far, it still does not work on my RT-AC66U. Have anyone tried it out and know if the dual WAN function has been fixed?
http://www.asus.com/sg/Networking/RTAC68U/HelpDesk_Download/

Please advise. Thank You.