Unless otherwise provided by law and except in such cases in which the court has continuing jurisdiction, a civil judgment or decree rendered in the Superior Court may not be opened or set aside unless a motion to open or set aside is filed within four months following the date on which the notice of judgment or decree was sent. The continuing jurisdiction conferred on the court in preadoptive proceedings pursuant to subsection (o) of section 17a-112 does not confer continuing jurisdiction on the court for purposes of reopening a judgment terminating parental rights. The parties may waive the provisions of this section or otherwise submit to the jurisdiction of the court, provided the filing of an amended petition for termination of parental rights does not constitute a waiver of the provisions of this section or a submission to the jurisdiction of the court to reopen a judgment terminating parental rights.