Asus RT-AC86U with g.fast MT992 modem - Speed issue

[Audin]

So I've recently moved house and had a g.fast line put in. The BT Smart Hub 2 I was given was hitting the full 160mbps as expected of the line but I was unhappy with the lack of router customisation or performance on online gaming. I managed to get a ZT Link MT992 modem from a BT Openreach engineer so I could use my Asus RT-AC86U that I used in my old house but I'm only getting a maximum of 140mbps.

Is this a problem with the ZT Link MT992 not being as good as the BT Smart Hub 2 (as a modem) or have I misconfigured something in my Asus RT-AC86U? I haven't altered any of the default WAN settings on the Asus RT-AC86U apart from entering the standard WAN username and password for BT, in PPPOE mode.

Any help or advice on how I can get the full 160mbps from my Asus RT-AC86U would be much appreciated. Thanks.

[Audin]

Forgot to add, on the MT992 the DSL light is always lit but the Internet light isn't. Is this normal?

I've switched back to the BT Smart Hub 2 for now as my kids have a meltdown if there's any downtime, so could anyone offer any advice on optimum WAN settings for the Asus RT-AC86U please? Or should be default do the job?

[Audin]

Anyone? Please...

[sarkyscouser]

I have just put an MT992 in front of my Unifi USG. I can get ipv4 pppoe working fine using the standard credentials, but ipv6 is another matter. The smart hub 2 I switched out got ipv6 no problem.

I'm on g.fast 330/50.

There is no interface for the MT992, it's just plug and play and I'm getting full speed.