3814656 - Why is the 'Transaction Amount' field grayed out in my request entry?

Why is the 'Transaction Amount' field grayed out in my request entry?

I found the 'Transaction Amount' field grayed out in my request entry. Even the Access Rights of Request Employee role is 'Modify' status, I still can't modify it. Sometime if an Amount Calculation Formula is set for a specific expense type in used Request Policy, this field will be displayed as grayed out and cannot be changed even the Access Rights of the field is "Modify" status in Forms and Fields configuration. , KBA , CON-REQ-REQ , Request , Problem