IPV6 and 374.43 Help

[sonarman]

I have Merlin 43 installed on my RT-AC66U. I am Timewarner as my ISP. When I connect my computer directly to my Cable modem, I get IPV4 and V6 addresses. If I run ipv6 speed tests(Multiple) i get 15Mbps down, 1Mbps up. if I then put my router in between the computer and the modem, i get V4 and V6 addresses, and when I the same tests, I get less that 1Mbps up and down. I selected Native for connection type. Anyone have any ideas?

Thanks in advance

Update: The issue appears to be related to QOS. I had QOS on for Vonage. If I shut it off. speeds return