Connect your PC/Laptop directly to your router
If you have an ethernet cable which can connect your modem directly to a device (e.g. laptop or PC), try connecting the device directly to the modem now - you can use either of the ethernet cables that came with your MyRepublic modem.
Doing this will diagnose whether the problem is with your Wi-fi connection or not. As soon as your modem is directly connected, run another speedtest to confirm if this fixed the issue.