Ubuntu – USB ethernet adapter: ‘Cable unplugged’ message while plugged in

If I understand your case right, and you have not already done so; delete the old network card from /etc/udev/rules.d/70-persistent-net.rules

Reason: The blacklist tells Ubuntu not to load it on detection of the hardware. If you have a configuration telling it explicit to load it later or another module depending on it loads, will it still be loaded. Unless you have also told Ubuntu how to "load" that module, look at the example, here we specify it to just run /bin/true or /bin/false instead of loading the module with modprobe eg.

Updated and corrected for your case:

Add one new line with the name of the module, sk98lin, at the end of this file /etc/modules. Now are we telling Ubuntu to load the sk98lin driver module at boot.

Then create the file /etc/modprobe.d/blacklist-marvell.conf and add the following on a line install sky2 /bin/false

Then run sudo depmod -ae

And yes, you will need to update your init-ram-filesystem with the command sudo update-initramfs -u

Restart.

If the above should not work for any strange reason, just remove all changes you did and try to do the dirty rc.local hack.

# Add the following to your '/etc/rc.local' file.
modprobe -r sky2
modprobe -r sk98lin
modprobe sk98lin

Save and restart.

Answer for followup question

The content of /etc/network/interfaces should be

auto lo
iface lo inet loopback

You have to either let the NetworkManager or the system(the interfaces file) configure your connection.

To let the NetworkManager do it, delete your old connection and click as picture show.

This kernel parameter solved the same issue for me (with a Dell DA200 USB3 dock):

usbcore.quirks=0bda:8153:k

which disables Link Power Management for the device. See also this bug report and this Github issue (for a different hardware with the same driver/NIC chip).