@sebastiankoh, sorry for the delayed response.
When I click on the “Enable expert button modes” page it flicks and that's it.
After the click on the “Enable expert button modes” button, you are supposed to see a screen that explains the permissions being asked and a request to grant those permissions.
When you click Allow, it hides the permissions screen.
Now, you should open the “Button mode” dropdown menu and select one of the expert modes.
After that, the extension should start working the way it used to.
Did that work?
Here is a demo of all button modes: https://youtu.be/SbzCMXoW3pA
@jeremyx98: I feel you. Just installed Opera GX and it is amazing. Will probably stop using Chrome because of Opera's built in VPN and Ad-blocker. This will be my new opera wallpaper. I wish I could find some more sci-fi themed wallpapers.