Please verify subscription status through the Purchase History section:
- Open the Settings app.
- Tap your name, then tap Media & Purchases. You might be asked to sign in.
- Tap Purchase History.
- If you see 2ndLine subscription under the Pending section, it means that the amount may be debited from your account but is not yet settled with Apple.
In such a case, Apple does not confirm a successful subscription to the app. You can read more about this from Apple's site here.
Once Apple confirms a successful subscription, the app will work fine.
In other words, if you see the active subscription under a recent date within the Purchase History section, but just in case the app is still not working for you, please contact us with details so we can provide you support.