Update: in the subscription header tap the circular-arrows icon, or just reopen the app — Happ updates the subscription automatically.
Re-add (if updating doesn't help):
- Via the bot: @SurfingVpnBot -> 🚀 Подключиться (Connect) -> ➕ Добавить подписку (Add subscription).
- In Happ: tap the i icon to the left of the subscription -> scroll down -> Add subscription.