A tribunal in Georgia shall recognize a modification of its earlier child support order by a tribunal of another state which assumed jurisdiction pursuant to this article or a law substantially similar to this article and, upon request, except as otherwise provided in this article, shall:

(1) Enforce the order that was modified only as to amounts accruing before the modification;

(2) Enforce only nonmodifiable aspects of that order;

(3) Provide other appropriate relief only for violations of that order which occurred before the effective date of the modification; and

(4) Recognize the modifying order of the other state, upon registration, for the purpose of enforcement.