js image effect script I made for my personal site doesn't work on LibreWolf, what is conflicting with the privacy settings?

There is no CORS going on, the very same script use canvas on two other sections, so I guess that's not the problem... it works on FireFox but breaks on LibreWolf:

https://privatebin.net/?401a54f23eea492d#6hEX1c73DVFHv7MJQaT5j6Nm4C9a29unnd4xzeeURpqU

Any idea what part LibreWolf doesn't like? I'd like to fix it to work.