I found a blog from "David Hamann" - "Sharing a VPN connection with another device on macOS Sierra/El Capitan" (I cannot add a link here, so it's better later google it), where you can find an explanation to share a connection from tunnelblink.
Answering your question, you can revert using:
$ sudo pfctl -e
$ sudo pfctl -F all
davidmelo
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Use the solution of @Gormo, worked for me in AX88179 UGreen ethernet dockstation.
https://developer.apple.com/forums/thread/651132