[Zubersoft]

That's really strange - I'm not sure why you had to toggle the settings around like that. It's possible that there was no setting saved in the OS for your preference as it had never been changed, so MobileSheets couldn't find anything and defaulted to 12 hour. Once you toggled the setting back and forth, then there was a preference MobileSheetsPro could retrieve, so then it knew to use 24-hour instead.

Mike