InDesign is not currently detecting US spellings that use 'ize' in text that is set as 'English: UK'. (example 'organize'). We have checked to make sure there are no local overrides, such as paragraph or character styles set to 'English: USA' (there aren't), and that the undetected spelling has not been added to the custom dictionary (they haven't been). Failure to pick up 'ize' spellings is a departure from previous behaviour and is quite problematic for our workflow. Other US English spellings (such as 'behavior') are being detected.