OnePlus / Oppo Phones - Connection issues in Japan

Due to the Docomo network no longer offering 3G coverage, we have found that some OnePlus / Oppo handsets are not fully compatible with the Docomo network and their services provided within Japan.

We believe that in most cases, this is due to devices failing to complete IMSI / VoLTE registration checks (due to the device not being fully compatible / whitelisted to access the Docomo 4G LTE network) and unfortunately, issues of this type are out of our control.

This can cause network connection / calling issues with our voice capable SIM / eSIM products but it can also cause general connection issues with data-only SIM card products as well.

Results can vary but if your device is affected by this issue, you may find that your phone initially connects to the network successfully (for approximately 24 hours) but once the temporary network registration has expired, the device may no longer be able to connect to the network. 

Alternatively, you may experience connection issues from the start or find that the connection remains intermittent.

In some cases, rebooting the phone may cause the device to connect to the network again for a brief time (but then the issue usually quickly returns).

A list of OnePlus / Oppo devices that may be impacted by this issue can be found below - 

Compatibility Issues

Incompatible Phone List

Please note that we have not had the opportunity to test all handsets from the OnePlus / Oppo range and so there may be affected devices that are not yet included in the list above.

Troubleshooting Suggestion:

If you have checked the relevant data setup guide (select your current product type from the list shown here) and all settings are correct but the issue persists...

Please edit the current APN (Access Point Name) profile again and try changing the "APN Type" to the setting shown below -

APN Type: default,ia

All other settings from the Mobal APN profile can remain the same.

Once you've made this adjustment, please save the profile (and ensure it's still selected as the active profile) and then test the connection. If there is no improvement, please reboot the device to refresh the connection and then test the service again after a few minutes.

Based on feedback from network technicians, making this adjustment can sometimes resolve issues of this type but unfortunately, there are no guarantees.

Issue Persists?

If the issue persists after completing the recommended checks above, it's unlikely that we'll be able to offer a solution (as compatibility issues between specific phones and networks are entirely out of our control).

We would therefore recommend that you contact the OnePlus / Oppo support team for your device to discuss the issue further.

You can then explain the issue and ask if they can provide more information or suggest any additional troubleshooting steps that may force the device to connect to the network.

If a solution cannot be found however, we can only recommend that you consider switching to an alternative handset (while avoiding devices from this range).

Phone not shown in list?

If your issue persists but your device is not included in the list above (and you believe it should be due to issues you've experienced), please contact our support team and provide -

• The IMEI number of your device (usually found by dialing *#06# from the keypad or by locating the "About Phone" section on your device.
  
  
• Details of the issues you experienced or screenshots of any error messages you received.
  
  
• Screenshots of your current settings such as the APN profile settings and your Network Mode setting
  
  
• A screenshot of the SIM management section on your device (the section that shows all currently installed SIMs / eSIMs and the preferred SIM for calls or data etc)