This is usually caused by either an issue with the device settings, or some conflicting app/software. Here's what to do:
- Ensure that Background App Refresh is enabled in Settings for Lockdown. Lockdown needs this in order to refresh itself and stay active. See how to turn this on in Apple's documentation here: https://support.apple.com/en-us/HT202070.
- Ensure that Low Battery Mode is set to off. Sometimes iPhones and iPads become overly aggressive in stopping background apps like Lockdown when this mode is enabled. See how to get to this setting in Apple's documentation here: https://support.apple.com/en-us/HT205234.
- Ensure that no other security products or VPNs are interfering with Lockdown. Lockdown is incompatible with many third-party VPNs and/or security products. Here's how to turn those other conflicting apps off:
- Open Settings app
- Tap VPN
- If there are any entries that are NOT "Lockdown VPN" or "Lockdown Configuration", tap the "i" next it
- Turn "Connect On Demand" OFF for those entries (again, entries that are NOT Lockdown)
- Open Lockdown again, and activate Firewall and Secure Tunnel
- Ensure that cellular data is turned ON for Lockdown. If you disable cellular data for Lockdown, it will be unable to process legitimate app requests and apps will appear to have no internet connection, despite your device having a strong cellular connection. Learn more about cellular data and Lockdown in this FAQ.
- Ensure that Lockdown is up to date (how to update apps), and then update your iPhone, iPad, or Mac to the latest version available: update iOS or iPadOS, update macOS.