Bigpipe seems to be having some sort of routing issue for me currently

I'm based in Auckland and on a Gigabit connection. I've restarted my router/ONT multiple times and have changed to a different router and the results are similar. I have also tested using Ethernet as well.

Speedtest with a server yields inconsistent speeds and high latency.

Testing with Spark server results in excellent latency but speed seems to be capped at ~280Mbps down

Testing with a 2Degrees server results in bad latency but good speeds that I'd expect over wifi, which is also what I'm used to getting prior to this.