glob expression excluding resources not working

Scratch that, the filter seems to work in the filter ‘Resource Group (with Subgroups)’ but doesn’t work in the filter ‘Resource Group’, which is also the only filter I can use in an Alert.

It seems that once you add an exclamation mark the filter goes completely empty. If I wrap a word in asterisks the drop down returns just words that match what’s wrapped. but if I type an exclamation mark at the start it doesn’t invert the filter and remove those entries, it just goes blank. 

I think there is a bug in the glob expression
Back to the drawing board :(