I have Home920 plan at home and noticed that my upload speed is around 250-300 when I do a speed test.
So I plugged my windows laptop into power, used a cable did a test using Speedtest App with same results. download around 920 upload 280
So I tried another windows computer - similar results.
I tried different speed test servers
I asked my mate to do at test at his place and got similar issues with upload on his and my pc.
He is on a different Isp but on similar plan 1000down 500 up
Tried with m2 Mac book at his place- upload is perfect.
Took his Mac book home upload is perfect - 450mbit.
So I tried Speed test at different location on different windows computers and upload speed everywhere was no more than 300mbit.
If you have a chorus fiber with speed 1000/500
Can you do a speed test at your windows computer and give me your result link it would be great