According to the only snippet on this I found in English, from March 20, 2018:
The Constitutional Court of Romania (CCR) has admitted on Monday the PNL and PMP notification regarding the draft law on the establishment of the Roman Catholic Theological High School in Targu Mures. “The Parliament cannot give individual laws that produce effects for a single legal person, and in this case it is a legal person. It is not a regulation on the relations between parents, pupils, students, a school was established,” CCR ...
The PNL (National Liberal Party) backed and backs Klaus Iohannis for presidency, who himself is a member of the German ethnic minority in Romania. So PNL doesn't seem incredibly xenophobic overall. So, why did they complain against the Hungarian-language Catholic school in Targu Mures?
(Also the leader of PNL and current Romanian PM, Ludovic Orban is of mixed Hungarian and Romanian ethnicity. He was also leader of PNL [but not PM] when that complaint was made.)