Key legal question
Whether the renewed overtime claim was barred by res judicata after the first case was dismissed following a claim withdrawal.
Extracted holding
A dismissal based on claim withdrawal generally has res judicata effect under federal law, even if the withdrawal concerned only the procedural right to sue. The cantonal distinction between waiver and withdrawal could not deny that effect here.
Extracted reasoning
Maternal res judicata is governed by federal law. Party-based termination decisions such as withdrawal, settlement, or acknowledgment usually become final. No exception applied: the withdrawal was not made at an early stage and there was no substantiated reservation to refile a better claim. Any possible defect in the declaration would matter only for revision, not for res judicata.