Hi Michael,
Both of these test look like they've been conducted on a device connected over WiFi. To help eliminate possible WiFi interference as the cause, can you perform another speed test on a device that is connected to your modem via an ethernet cable. Make sure that any other devices are disconnected from the modem or turned off so that we are getting an accurate picture of the speeds available to the whole of your service rather than just one device.
If the speeds are better when your device is connected by cable then it could be a WiFi issue. Have a look at the following WiFi troubleshooting article, which you may find resolves your issue. It contains tips, an online tool and a downloadable app which can help in optimising your connection. I usually find that changing the channel the modem transmits the WiFi signal on can help. You may have to try a few different channels before finding an optimal one.