Short answer: Start with the least destructive checks: refresh the subscription, confirm the client imported the subscription URL, compare Wi‑Fi and mobile data, then test another current route.
Run the same test on both networks
Use the same device, same client and same server. First test Wi‑Fi, then mobile data. If only mobile data fails, the problem moved from “app setup” to “network path”.
Refresh the subscription while on mobile data
Some clients keep stale addresses until you update the profile. Refreshing while connected to the problematic network can reveal whether the subscription endpoint itself is reachable.
Try another current route
Do not randomly change every setting. Pick another route from the same subscription, test one website, then switch back if needed.
Check private DNS and battery restrictions
Android private DNS, aggressive battery saving and background network limits can make VPN clients look broken even when the route is fine.
Report the operator and region
Support can act faster if you include mobile operator, approximate region, client app, server name and the exact time of the failed test.
When to contact support
If the profile is current and the same route fails repeatedly on one provider, contact support through the bot. Include device, OS, client app, network type, route name and time of test. Do not post private subscription links in public chats.
Mobile-data isolation test
Use the same phone, same client, same subscription and same route. Test on Wi‑Fi, then switch only the network to mobile data. If the result changes, the app configuration is probably not the primary issue. Now test one alternate route on mobile data and record the operator and approximate region.
Common mobile-only causes
- Carrier filtering or poor international route reachability.
- Private DNS or carrier DNS behavior.
- Battery optimization stopping the client in the background.
- IPv6 or captive-network behavior that differs from home Wi‑Fi.
Do not solve a mobile-route problem by rebuilding every rule. Keep the setup constant and report the network difference.
What support can do with operator data
Knowing the mobile operator, region and time of failure helps identify route-specific blocks or bad paths. Without that context, the only visible fact is “mobile data fails”. With it, support can compare reports and decide whether a route refresh or alternate direction is needed.
Separate mobile data from the profile
If the same profile works on Wi‑Fi and fails on mobile data, the subscription is probably not the broken layer. Record the carrier, route, time of test and visible IP result before changing the client.
Need a mobile-data route?
Open Foli, refresh the subscription and try a current route before rebuilding the profile.