USB C to ethernet adapter doesn't work in Catalina

I have been unable to get my USB C to ethernet converter working in either my 2020 Macbook Pro or my older 2016 model, both with Catalina 10.15.5 installed. This makes me think it is a software issue, and I am surprised a proprietary Mac device doesn't work with their own OS. Then again it is over 18 months old, so may as well be last century in Mac age: so do I need to buy a newer interface? Is there a driver or tweak I need to do? The device does not show up in the THunderbolt or USB listings in System Report. I have already tried countless reboots and SMC/PRAM resets. The Model no. on the adapter is A1277.