Did the defendant have the right to file a lawsuit, and the court to accept the case?

In accordance with the seventh part of Article 147 of the Law of Ukraine "On the Judiciary and the Status of Judges", taking into account the impossibility of courts to administer justice during martial law, the Supreme Court is authorized to change the territorial jurisdiction of court cases. He did this by adopting the order dated 06.03.2022 N 1/0/9-22 "On changing the territorial jurisdiction of court cases under martial law" - https://ips.ligazakon.net/document/VSS00822?an=1.

This order states that cases from the Rubizhan City Court of Luhansk Oblast and the Swativ District Court of Luhansk Oblast are transferred to the jurisdiction of the Pavlograd City District Court of Dnipropetrovsk Oblast.

Therefore, the court from the Luhansk region should transfer all the documents in your case to the Pavlograd city-district court of the Dnipropetrovsk region. It could happen that these documents were lost or even destroyed during hostilities, so they did not have time to get to the Pavlograd City District Court of the Dnipropetrovsk Region and the case was not opened there, there is no data on it in this court. Therefore, your new statement of claim on the same case was accepted and everything here is completely legal. After all, before accepting the application, the court checks whether there is a similar case in another court.