Gorhill, i've found an issue with the new update 1.28.0
When privacy.resistFingerprinting in about:config is set to true, double tapping Ctrl doesn't work. Setting it to false will fix it, but setting it back to true Ctrl does nothing again. You don't have to restart the browser to test it either.
i don't think there is anything you can do about it as i've seen privacy.resistFingerprinting similarly mess with other things with other extensions.
You can set filterAuthorMode to true in uBO's advanced settings to get permanently back the creation of _allow_ rules if double-tap ctrl does not work or if you prefer to not have to double-tap ctrl key.
