I hadn't been paying attention and didn't realise the Runner plan was now up to 500 Mbps download, choice.
I ran a SpeedTest from a wired connection that I know from past experience can clock up to at least 900 Mbps on a speedtest (with a former provider), but it maxxed out at 320 Mbps or so. This is what I used to see when the plan was still 300/100. Yes, I am aware that Speedtest won't necessarily get the full speed, etc.
The power was out a couple of weeks ago and everything was offline for a good few hours, so I'm thinking it's not just a case of "reboot and get a higher-speed session". Does anyone have any ideas?