One plus ace2 can't receive short messages in Japan.

What you want to ask is why one plus ace2 can't receive short messages in Japan? Operator settings, roaming settings.

1. Operator Settings: Different operators have different settings for SMS service. Check whether the APN (access point name) and SMS center number of the operator are set correctly on the mobile phone.

2. Roaming Settings: When using the mobile phone in the international roaming state, you need to turn on the roaming function to receive short messages normally, so as to ensure that the roaming function is turned on and the available roaming operators are selected correctly.