Background Restriction Mechanism
Android and iOS strictly limit third-party app activity in the background when the screen is locked. If the app lacks unrestricted priority, the system closes the background tunnel process after 5–15 minutes of inactivity.
How to Stabilize the Connection
- Disable battery saver optimization in the system settings for your VPN app
- Switch the client protocol from OpenVPN to WireGuard or VLESS (they handle network switching better)
- Enable the Always-on VPN feature in your system network settings
- Pin the app card in your smartphone's recent tasks menu