Is it possible to change the Seniority date for a worker when he's having multiple assignment

Summary:

Hello,

We're trying to update Seniority date for Employees but when we try to update Seniority date in "Person Management", the following error message is displayed : "You can't change the legal employer hire or start date if multiple assignment records exist for the same date. You must remove the records to change the date. (PER-1531708)"

So do we have the possibility to update Seniority date in this case, or there's a workaround ?

Thanks,

Alexis