Origam entity - database function

When I used a database function to calculate entity field from two others entity fields, this field doesn’t recalculate after jump to another field as usual when using built-in origam function.
Field recalculate only after save and reload form. Is there a way for recalculate db function filed after change active form field as works build-in functions ?
Typically 1st field = 2nd field + 3rd field - this is evaluated after change 2nd or 3rd field and tab to other field. DB function doesn’t work like that.