Weretigers (and all lyncathropes; Monster Manual p. 210) have the Shapechanger trait:
The weretiger can use its action to polymorph into a tiger-humanoid hybrid or into a tiger, or back into its true form, which is humanoid. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn't transformed.
(Similar language can be found in MM for all lycanthrope types, not just weretigers.)
So if a weretiger PC in humanoid form wears studded leather armor and has a dexterity score of 16, say, it will have an AC of 15 (12 + DEX mod). If that weretiger polymorphs into its tiger form, the armor isn’t transformed with it, so does it keep its AC with the armor (“its statistics... are the same in each form”) or does it lose the AC provided by the armor (since “any equipment it is wearing... isn’t transformed”)?
Does a lycanthrope's AC change when shapechanged?
To clarify, my confusion lies with what seems to me to be a contradiction. Either the lyncanthrope in animal form retains the AC it had in humanoid form (because its statistics are the same for each form), or its AC is possibly lowered (because its armor doesn't transform with it and I assume said armor no longer fits so its AC doesn't benefit from that armor). To stick with the example above, say the weretiger PC clad in studded leather armor and in humanoid form with that AC of 15 transforms into a tiger. The armor is no longer effective—it doesn't fit the tiger's shape or size and falls (or bursts) off. Does the tiger have an AC of 15 (its statistics are the same) or 13 (because it loses the armor's bonus to AC)?
Note: Since this question is in regards to PC lyncanthropes, not monsters or NPCs, the AC listed in the stat block for each type of lycanthrope doesn't satisfy my question.