@ALL_SYS_PWRGD 

I think if the internet is fine, there is no need to change any settings otherwise it might make things worse.

But if you are interested, you could try to enable SRA under Advanced>Network settings>DSL settings.

The router did appear to have an issue yesterday. All of a sudden, the Internet cut out. I logged into the router to see what went wrong. It was telling me to configure the DNS manually.

I rebooted and it reconnected. However I noticed that the speed was at 79999/20000 which has never happened before and the SNR margin dropped from the usual 3.4dB to -0.5dB. This did not last. It quickly resynced at the speed I usually get with the correct SNR margin.

The downstream accumulated 935 errors not too long after resync. These have now stopped. Upstream is just slowly accumulating errors. I'd say it rises by around 10-15 an hour. Not sure if this is a sign of a faulty router. It's not looking good that's for sure. Hopefully I don't have any further issues.

  @ALL_SYS_PWRGD 

I think the router is faulty. I have noticed that when I do a speed test and it jumps to the upload test, I get insane ping spikes (we're talking anywhere from 200-3000ms ping). The spikes can be seen on speedtest.net and also when pinging something like 8.8.8.8 via CMD while running the upload test. 

The spikes occur on Ethernet and Wi-Fi on both a laptop and desktop PC. Download is OK. It spikes a little (due to bufferbloat), but it doesn't really go above 40-50ms ping. It's the upload test that causes massive spikes.

I went back to the SR203 hub, re-ran the test and the spikes returned to where I expect (between 20-40ms ping). That's a big difference and tells me the issue is the router.

Is there anything that can be done to resolve those spikes? Or is it a bad router? It's a shame because I liked the router. The Sky Hub is too basic.

Decided to upgrade firmware to see if it'd help. It did not. There's still insane ping spikes/packet loss when an upload speed test is run. I don't know what would cause this. The spikes aren't this bad when a download test is run.