Automated date due to change in dropdown list

Hi folks!

We're trying to set up a sheet where we are able to automated fill out different date columns due to a change within a dropdown column.

If entry of the status dropdown is changed to pending, the current date should be displayed in the Date Pending column and - important - being locked for any changes. So that if the status is changed again to another value (e.g. Start) the date in the Date Pending column stays the old one, but the current date is displayed in the Start Date column. I hope this was understandable 😣

First try formular was =IF(Status@row = "Pending"; TODAY(); "") For sure that does not work as it did not contain the requirement of lock the first date entered. The moment the status is changed to another value, the date in the Date Pending column is deleted.

Anyone any thoughts on this?

Thanks and best regards,

Sebastian