In edit mode the dynamic dropdown field should display the value stored in the database, even if that value is no longer available. Only in the moment when you click on the dynamic dropdown field you will not have the original value as a selectable option as it has been removed.
An alternative would be to just pass the timesheet ID to the REST endpoint, which can be then modified to return the original option, if necessary.
Tempo Products | Tempo Timesheets |
Tempo Platform | On-Premise |