Hi @anoyed,
Have you tried changing the channels that the Sagemcom broadcasts the Wi-Fi signal on, you can use free smartphone Apps like this to see what channels are being used within range of your smartphone, you can then change your router to use channels that are less congested. Would just be interesting to see if this got the speeds back to something good.
Be aware that the Sagemcom router has a feature called 'Wi-Fi Optimisation', this means it can change the Wi-Fi channel itself, overriding what you have set it to, it can randomly do this after minutes, hours or days !. So if you do find a channel that works well, but then things go bad again, check to see if the router has changed channel to something different to what you set it to. If you do experience this problem then just post back here to ask the Support Team to disable the 'Wi-Fi Optimisation' on your router, once that is done it will stay on whatever channel you set it to.
But if changing channels is not making any difference, then your original request of a replacement router might be the best way to go, the support team here would be able to to help with that.
