Ah, maybe I didn’t properly fix the :not() validation issue you raised previously. There is actually red warning in the code editor too, but it’s hidden behind the ellipses at the top left, it becomes visible if you shift the CSS selector code down a line. I will investigate!
Thanks for reporting this Norm. I got a bit side-tracked with the :not() issue, but I will make some time to work on it next week. And check the syntaxError issue too.