The internet speed is way slower than my Plan

Hi,

I activated my 2000Mbps plan yesterday, which is expected to support the upload speed up to 300Mbps.

I've been tested it multiple times yesterday and today. The download speed is at the range of 100Mbps-600Mbps, while the upload speed is only 6Mbps consistently.

Note that I also use an ethernet cable to connect my laptop directly to the Modem and tested it wiredly.

I am using the Netgear CM2000 Modem which supports up to 2.33Gbps speed, so it should not be the bottle net.

I used to use the Comcast business "Business Internet 100" plan and it has not been terminated yet (it's out of custom service's working hours). I am afraid that it has something to do with it. How can I resolve this issue?

Thanks,