slow internet speeds using own router. fios gigabit+tv with Asus RT-AC68U router

[Aminp]

Thanks in advance for any advice/suggestions.  I recently switched from RCN 500mbps to Fios gigabit+TV. I received the new 3100 gateway/router along with the usual ONT box.  I want to use my own router but my download and upload speeds are maxing out at 250 mbps using the asus but was getting 940/800 using the FIOS router. Im trying to understand why the significant drop?

I have performed the following steps in switching to my asus router:

- Purchased Actiontec 2.0 moca so I get the on demand TV services.  The MOCA is connected to the One fios STB and ONT via coax and to my asus router via LAN ethernet port 1.

- Connected my Asus to the ONT via cat6 cable using the WAN ports. I've tried cat5e too

- Requested the release of the DHCP lease through verizon support. Powered the router down for 10 mins before the verizon support person said to power on again

I have a desktop PC that is connected via LAN (cat5e) to the ASUS router ethernet port 2. The router LAN ports support gigabit and the desktop network card is gigabit - i was getting gigabit speeds wth the same setup with the exception of the router being the fios 3100 device.

Does anyone have any thoughts as to why the speeds on my asus router is maxing out at ~250mbps?