Why does my Start date column and my Received date column put in the same date?


I created this sheet 5 years ago to log contracts when received, the start date and end date. Just about a month ago, my start date and received date column input the same date. As if they are linked or joined but I cant see anything. Has anyone else had this problem? What can I do to fix it. I am now concerned this may have been going on for a while and my data is not accurate.