Whether res judicata or collateral estoppel should apply when the initial trial did not have a full and fair opportunity to litigate the merits

No question identified. : 1 QUESTON(S) PRESENTED , 1. Ifin the initial trial, the Court refused to hear litigation of the merits, . should future Courts apply res judicata or collateral estoppel to the initial judgment when the initial trial did not have a full and fair opportunity to litigate the issue of merits? 2. Cana Court claim res judicata when the defendant did not plead an affirmative defense per Federal Rules of Civil Procedure, Rule 8, without a cite from any authority?