I use the app to unlock my door phone. I am very sure that my call is normal. And I checked the account registration information is good.  Then I verified many times that the door really couldn't be opened, so I went to the cloud platform to check the unlocking configuration of my door phone and there was no problem. However, it seems that the DTMF settings on the device side are different from the cloud. It might be because I forgot to synchronize the DTMF setting from Cloud to the device again after I have had changed the DTMF setting on the device web interface. Therefore, I restarted the device again, and then successfully issued the cloud configuration, and the unlocking problem was solved. I found that if problems such as access control failed, you might as well start by checking to see if the cloud configuration has been overridden by the local configuration on the device.

the DTMF in the device

DTMF Setting in the Cloud