Flex Pitch on/off for regions in Logic 10.5.1

Hi everyone. I want to have my Flex Pitch edits turned on or off on different regions of a lead vocal track in Logic 10.5.1 but can’t find the way. I know that the Show/Hide button doesn’t turn anything off but there is no “off” option in the flex mode drop-down in the region inspector (see screen grab). The blank area below the Flex Pitch entry can’t be selected and choosing Flex Pitch again doesn’t remove the tick. Am I missing something? Thanks in advance.