Can not change date format on Google Spreadsheet

i tried to block B column to change the date format, but why it only changed the first row. I need to make a format like the first column of B to do importrange formula. Any suggestion? Thanks!

Please share us the Spreadsheet File with Edit Permission, so we can check this for you and possibly fix the problem. Share it with support@jotform.com. 

Also, what is your preferred date format? Note that you can change this in the field itself. Please try that.