I have a Motorola MT7711 modem and get 645 mbps on my wired PC. I am only getting 1 mbps on my iphone and other devices while sitting next to my modem. Why can't I get better WiFi? The MT7711 is capable of 1900 mbps.
Sounds like a Motorola issue, given how you paid good money for it and your wired connection is fine, I'd start with them.
I'd suggest a firmware update, factory reset, either warrantying or even buying a replacement to see if the issue was specifically tied to that unit. A few amazon reviews do point to the same issues, but it seemed pretty rare.
Here's their contact info:
|US and most other countries:|
|1-800-753-0797 or 1 617-753-0562|
|UK||+44 800 023 9083|