Very slow data rate / throughput on wireless Aruba access points, RADIUS authenticated.

Hello Experts,

We have 13 access points from Aruba (model number 225) and Aruba controller (model 7010).

We have a corporate SSID which is published only to domain-joined laptops via GPO. Then its also RADIUS authenticated.

We also have a Guest SSID which is broadcasted normally and secured with a WPA key.

All the APs and the laptops are fairly new and support 802.11 ac 40MHz

The Corporate internet line is separate 100Mbps
The Guest internet line is separate 100Mbps

When I connect to the guest internet via wifi, I am getting speeds of up to 75Mbps when users are connected.
When I connect to the corporate internet via wifi I am getting speeds of only up to 7Mbps when users are connected.
When I connect to the corporate internet via LAN, just to check, I am getting speeds of up to 60Mbps.

I also tried to connect a cable directly to the Aruba controller and tried the speeds and its good @ 65 to 75 Mbps.

I checked on the Aruba controller dashboard and was surprised to see that all the corporate clients are connected to n 40 Mhz even if the AP is broadcasting ac 40Mhz.

Please if someone could assist?

Thanks