The ASIX AX88772A driver sometimes works if the Realtek driver fails. You can find that on ASIX’s official website. For Linux (Ubuntu/Debian/Raspberry Pi) Plug it in. It should work immediately with the sr9700 or sr9800 kernel module. Run this to check:
You almost certainly don’t need a specific "Frontech" driver.
Go to Station-Drivers.com or Realtek's official site and search for: "Realtek USB FE/Fast Ethernet Family Controller Driver"