StoreKit.product.purchase returns success, but subscription does not appear in Settings

Description: We are developing an iOS app that offers only one auto-renewable subscription.

Recently, a user who had not subscribed for over a year purchased the subscription again through our app. However, when they checked Settings > Subscriptions, the new subscription did not appear. Instead, only their past subscription history was visible, and there was no option to cancel the new subscription. We have verified this issue with a screenshot provided by the user.

Additionally, we checked our app’s logs and confirmed that StoreKit.product.purchase successfully returned .success, indicating that the purchase was processed correctly.

Code used for purchase:

let result = try await product?
    .purchase(options: [
        .appAccountToken(uuid)
    ])
switch result {
case .success(let verificationResult):
    switch verificationResult {
    case .verified(let transaction):
        addPurchaseLog("verificationResult.verified.")
    case .unverified(_, let verificationError):
        addPurchaseLog("verificationResult.unverified.")
case .userCancelled, .pending, .none:
        addPurchaseLog("verificationResult.userCancelled or .pending or .none")
@unknown default:
        addPurchaseLog("verificationResult.unknown.")
}

Despite the successful purchase, the new subscription does not appear under the user's active subscriptions. Could this be a bug in StoreKit? If there are any known issues or workarounds, we would appreciate any guidance.

Environment: Xcode: 16.2

iOS version: 16.0+