Is EU law, in particular Articles 20 and 45 of the Treaty on the Functioning of the European Union, Article 4 of Regulation No 883/2004 and Article 7 of Regulation No 492/2011, to be interpreted as precluding a provision of national legislation, such as Article R 532-3 of the code de la sécurité sociale (French Social Security Code), which defines the reference calendar year, for the purposes of calculating family allowances, as the year before that preceding the payment period, and results, in a situation where the income of the person claiming the allowance has risen substantially in another Member State, and then fallen [following] his or her return to his or her Member State of origin, in that person being deprived, unlike residents who have not exercised their right of free movement, of part of his or her family allowance rights?