In Tomb of Annihilation the prospect of getting lost/turned around in the jungle is written explicitly into the rules: “The Land of Chult” and its “Navigation” section have the party navigator making a check every day, and they may become lost if the check goes awry.
But my party has a ranger, favored terrain of forest. Whose group, due to Natural Explorer, “can’t become lost except by magical means.”
Nothing suggests that difficulty finding one’s way in the
lion’s Tyrannosaurus’ share of Chultan jungles is magical. It’s just mundane bushwhacking-sometimes-goes-awry.
So do groups playing Tomb of Annihilation who include a (forest) ranger simply dispose of the whole “Navigation” section while in the jungle?
(We’ve ruled that forest==jungle for Natural Explorer’s purposes. As does Jeremy Crawford. If you disagree hold your ire and imagine we were talking about coast, or swamp, or mountain; all of these are Natural Explorer candidates and might be where navigation checks would be indicated in ToA.)