async endCombat() {
    await super.endCombat();
    this._recoverUses({ turn: true, turnEnd: true, turnStart: true });
    return this;
  }

The _recoverUses is always triggered.

It might be down to Foundry to reimplement the endCombat in a more extensible friendly way (but the system should find a way to patch this bug essentially faster via deleteCombat probably).

This is from Foundry's code base

 async endCombat() {
    await foundry.applications.api.DialogV2.confirm({
      window: {title: "COMBAT.EndTitle"},
      content: `<p>${game.i18n.localize("COMBAT.EndConfirmation")}</p>`,
      yes: {callback: () => this.delete()},
      modal: true
    });
    return this;
  }

The way the deletion is hidden inside the dialog.yes means that the subclass caliing super.endCombat() can't distinguish confirm vs cancel from the return value alone.