I upgraded from 5.4 to 5.11 kernel version and now it works all, the WIFI, the Ethernet, the screen brightness and volume keys of the notebook. However I had to do one of the following things: disable the secure boot, or sign the kernel. I opted to do the first one first, then once with the system running I signed the new kernel and activated secure boot again.Also I came across this issue: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1859287
If you read through it you see that it was working and then someone else with Ubuntu 20.04 is having the same issues again. So it might be worth a try installing a newer kernel since according to the other source I linked says that the wifi should work with kernel 5.7 and above.