1. Check TE50 terminal logs.
After configuration parameters are changed at 07-05 09:08 48 on the web interface, the terminal can be successfully registered. Then an API user changes the password at 07-06-00:10:58, SIP registration fails at 00:11:31 with an error saying that the user name or password is incorrect. According to confirmation with onsite engineers, the login address of the API user is the address of another SMC2.0.
2. Log in to the IP address of the API user. It is found that the mentioned terminal is added on this SMC2.0 in manageable mode.
The mentioned terminal stays online on another SMC2.0. Ask onsite engineers to delete this conference site and then add it in unmanageable mode. The problem is then solved.