Ubuntu 20.04 slow download speed (wired network)

I have a 1Gbps connection and for some reason the download speed is very slow on Ubuntu 20.04 (using a wired connection not wifi). I tested several times using speedtest.net and got very different results on 2 different distros.

Ubuntu 20.04 speedtest results

Download speed  |  Upload speed
72 Mbps            450 Mbps

I tested using Pop!_OS distro live CD and the results were totally different

Download speed  |  Upload speed
996 Mbps           444 Mbps

What could be the problem?

Solution 1:

Thanks to @FedonKadifeli I was able to fix the problem, this seems to be a known bug. The solution was to pass a kernel parameter to grub.

https://bugs.launchpad.net/ubuntu/+source/linux-oem-5.10/+bug/1930754

The trick is to set the boot kernel parameter "pcie_aspm=off" in '/etc/default/grub'

Like this:

GRUB_CMDLINE_LINUX_DEFAULT="splash pcie_aspm=off"

After that run;

update-grub

pcie_aspm is some sort of power management thingie which probably puts my networkcontroller to sleep or something.