This is usually a default option on OnePlus and Pixel smartphones. However, since the latest Android update most devices now have random MAC address enabled.
When connecting to WiFi@Brunel and inputting the configuration settings, click on Advanced > Privacy > Randomise MAC Address. Ensure this is set to "Use Device MAC".
If you are already connected, in your WiFi settings click on the gear icon next to WiFi@Brunel or edit this connection. This will take you to the configuration page, simply scroll down to Advanced > Privacy > Randomise MAC Address and change the settings to "Use Device MAC".
Once this setting is changed and the device is registered with the correct MAC address the internet connection should restore instantly.