Joined Cases C-496/18 and C-497/18: Judgment of the Court (Fourth Chamber) of 26 March 2020 (requests for a preliminary ruling from the Fővárosi Törvényszék — Hungary) — Hungeod Közlekedésfejlesztési, Földmérési, Út- és Vasúttervezési Kft. (C-496/18), Sixense Soldata (C-496/18), Budapesti Közlekedési Zrt. (C-496/18 and C-497/18) v Közbeszerzési Hatóság Közbeszerzési Döntőbizottság (Reference for a preliminary ruling — Public procurement — Review procedures concerning the award of public supply and public works contracts — Directive 89/665/EEC — Procurement procedures of entities operating in the water, energy, transport and telecommunications sectors — Directive 92/13/EEC — Public procurement — Directives 2014/24/EU and 2014/25/EU — Review of the application of public procurement rules — National legislation which allows certain bodies to initiate a procedure of their own motion where there has been an unlawful amendment to a contract which is in the course of being performed — Time-barring of an authority’s right to initiate a procedure of its own motion — Principles of legal certainty and proportionality)