If the speeds are the same for wired and wireless, that would seem to suggest the situation is with your system. A link speed is normally for a local network and does not look at the Internet speeds. For instance, the Ethernet should show 1000 Mbps if you have a GB Ethernet adapter.
The Phone uses wireless, I assume, and not the Cellular data which goes directly to the phone. Network speeds, as far as wireless is concerned, will be lower depending on how many devices are involved. But the Ethernet speeds should be fairly constant. If you were to have a Dell system, there is software installed on some of those systems which can limit bandwidth. A Qualcomm device is now related to Rivet Networks with the Killer Wireless devices which may have such software installed. That software is called SmartByte and may show up if you go into the Control Panel and then the Programs and Features to see if it is listed.
There is a possibility, if you have installed software from your ISP, that it could be involved. You might check any settings related to QoS which may be managing your bandwidth.