Possible causes and solutions:
If you hear your own echo during the call, the peer party may have a call problem or the network is unstable. It is recommended that you check whether other call objects and the call environment have the same problem.
If the other party gives feedback on your echo during the call, it is recommended that you check whether your finger blocks the MIC hole during the call, change another call object, or try the call environment.
If you hear echoes in different calls, it is recommended that you back up data and carry your handset purchase voucher to ZTE after-sales offices for repair.