1. Check whether the two SIM cards can both be identified

If your phone does not display the signal bars of two carriers, it is possible that only one of your two SIM cards has been identified. In this case, remove and then re-insert the SIM cards. Refer to the link below for further guidance:

You can also refer to My HUAWEI phone is unable to detect the SIM card.

2. Make sure that no default calling SIM is set

Open Settings, search for and touch SIM card management, and set Default calling SIM to Not set.

3. Make sure that the pre-installed phone app is set as default.

Go to Settings, search for and touch Default apps > Phone app, and select Contacts (default).

4. If the issue persists

If the issue persists, please call the Huawei customer service hotline for further assistance. We will do our best to address your needs.