You land in Tokyo, Singapore, or Bangkok. Your eSIM shows four or five signal bars. You open Google Maps. It does not load. You try Safari. Times out. You have signal but no internet. Here is what is actually happening and the fix in order.
Why Signal Bars and Internet Are Two Different Things
Signal bars show whether your phone has registered on a local mobile network — essentially whether the tower sees your phone. Internet requires an additional step: your phone must be allowed to send and receive data through that network connection. Data Roaming is the permission that allows this second step. Without Data Roaming enabled on your travel eSIM line, your phone registers on the network (signal bars) but cannot exchange data (internet).
The Fix: In Order
Fix 1 (solves 80% of cases): Enable Data Roaming
iPhone: Settings, Cellular, tap your travel eSIM line name (Japan Data, China Data, etc.), Data Roaming — toggle ON.
Samsung Android: Settings, Connections, Mobile Networks, tap your eSIM line, Data Roaming — toggle ON.
Wait 30 seconds. Open Google Maps. If it loads: done.
Fix 2: Confirm the correct data line is selected
iPhone: Settings, Cellular, Mobile Data — confirm your travel eSIM is selected as the data source, not your home SIM.
Samsung: Settings, Connections, SIM Manager, Mobile Data — confirm eSIM is selected.
Fix 3: Force network re-registration
Toggle Airplane Mode ON for 15 seconds, then OFF. Wait 60 seconds. The phone re-registers on the local network with the corrected settings. Test Google Maps.
Fix 4: Manual network selection
iPhone: Settings, Cellular, tap eSIM line, Network Selection, disable Automatic, let it scan, select the local carrier manually, wait for connection. Then re-enable Automatic. This forces a fresh registration.
Fix 5: APN settings (rare but relevant)
Some eSIM providers require manual APN configuration. Check your QR code email from your eSIM provider — it may include APN settings. If so: Settings, Cellular, tap eSIM line, Cellular Data Network, enter the APN details exactly as provided.
China-Specific: Signal but Google Blocked
If you are in China and BBC.com loads but Google Maps does not: your eSIM is working correctly but lacks international routing. Google is blocked by China's firewall at the network level. An eSIM that routes through Chinese local servers cannot reach Google regardless of signal strength. You need a China eSIM with confirmed international routing through Hong Kong or Singapore. This is not a signal problem — it is a routing problem.
UAE-Specific: Signal but WhatsApp Calls Blocked
If WhatsApp text messages work but voice calls do not in Dubai or Abu Dhabi: this is UAE's VoIP regulation, not an eSIM problem. WhatsApp voice and video calls are blocked on all UAE local connections. Only an eSIM with international routing bypasses this block. Text messages work on any connection; calls require international routing.
After All Five Fixes: Contact Support
If after completing all five steps in order you still have signal but no internet: contact your eSIM provider's support with your phone model, iOS/Android version, and the specific carrier your eSIM connected to (visible in Settings, Cellular, your eSIM line). In rare cases the eSIM profile itself has a technical issue that requires provider intervention.
FAQ
Why does Data Roaming turn off sometimes by itself?
iOS updates occasionally reset Data Roaming to OFF as a safety default to prevent unexpected roaming charges. After any iOS update: immediately check Data Roaming is still ON for your travel eSIM. This single step prevents 80% of post-update eSIM connectivity issues.
My eSIM shows Connected but speeds are extremely slow — what is happening?
Possible causes: the plan's data allowance is exhausted and the eSIM has throttled to 0.1-1 Mbps continued access, or network congestion at a busy location. Check remaining balance in your provider's app or email. If balance is zero: purchase a new plan or top up. If balance remains: the location may be congested — try toggling Airplane Mode to reconnect to a different cell tower.
The eSIM was working, then stopped mid-trip — why?
Most likely: data allowance exhausted. Check your provider's app for remaining balance. Second most likely: the eSIM line was switched away from being the data source — check Settings, Cellular, Mobile Data that your travel eSIM is still selected. Third: iOS update reset Data Roaming — check the toggle.
Still having issues? Our eSIM plans come with email support. Japan eSIM on Docomo — if it connects to Docomo towers and Data Roaming is on, it works.