Looks like one of “Device recognition blocking” features is replacing return value of WebGLRenderingContext getSupportedExtensions function with null, while there is fingeprint JS libs that always expects that it will return Array.
I encountered such a problem when registering on a fastmail website, the registration form just broke when I clicked submit
Maybe we can just return empty array instead of null? That will prevent broken JS code, and still protect against fingerprinting