Do representatives of the TCC have the right to serve a summons without proper registration?

I recently read news about a court decision in Zaporizhzhia which stopped the illegal serving of a summons due to the lack of proper registration. I am interested in whether representatives of the TCC have the right to serve summonses at all without this registration. What are the legal consequences for individuals who were served a summons in violation of the procedure? Can such actions by the TCC be challenged in court?