100mbps service only getting 30mbps download speeds

I need some help troubleshooting an issue. I  signed up yesterday (3/19/20) for the Performance Internet service at 100mbps. I previously had performance starter at 25mbps. Everything has been finalized, but I am still only getting 30-38mbps today. My upload speeds have improved from 1-2mbps to 4-5mbps as expected. 

I have an Motorola MB7220 (8x4) modem. It's rated for 343 mbps speeds, and is approved for 100mbps through comcast. I have the modem connected to an Asus RT-N12D1 wifi router. I disconnected the wifi router and plugged my laptop directly into the MB7220 modem. When I ran a speedh test there, I got 100-115mbps downloads. I used the same ethernet cable to plug in from the modem to the laptop as I have been using to connect the modem to the wifi router. 

I reset the wifi router to facotry settings, and I updated the firmware to the latest version as well. I'm still only getting  30mbps through the Asus wifi router. I checked to confirm that I am on 802.11n so I should have the abilit to connect at well over 100 mbps. 

I also hav ea TP-Link repeater on the network, but I get the same speeds whether I am connected to the repeater or the Asus wifi router. It seems the only way I can get the actual download speeds is being connected directly to the modem. 

So, the question is what might be the issue. It obviously seems to be an issue with the wifi router, but I can't figure out what that may be. Could there be something on Comcast's side that has the wifi router limited to 30mbps?