This repo is extremely helpful but I believe the instructions for the ETH.begin() for the Arduino library is outdated. This format is working:

ETH.begin(ETH_PHY_LAN8720, 1, 23, 18, 16, ETH_CLOCK_GPIO17_OUT);
not the defined below:
ETH.begin(1, 16, 23, 18, ETH_PHY_LAN8720);

(I am using the ESP32-eth01 by WT)

Let me know if I'm correct and change if it is, Thanks!