Dates vanishing in seconds

edited 11/19/21 in Smartsheet Basics

I have a master spreadsheet in which there are few projects with start and dates I already entered earlier. When I am trying to enter start and end dates to some of the other projects/rows today, the date I am entering immediately vanishing though there are no predecessors or dependencies to that particular task and also after changing the project status too. A ticket has also been raised but I am in the need of an immediate response.

Please help me at the earliest in this,

Thank you all