1, the mechanical handle is stuck: may be the mechanical handle internal parts stuck, resulting in the inability to push to the normal position. You can try to gently shake the mechanical handle to see if the problem can be solved.
2, the mechanical handle is damaged: if the mechanical handle has been hit or wear and tear after a long time of use, it may lead to mechanical handle can not be pushed to the normal position. In this case, you need to replace the mechanical handle.
3, the mechanical handle connection is loose: if the mechanical handle connection is loose, may lead to mechanical handle can not be pushed to the normal position. You can check whether the mechanical handle connection is loose, if so, you can try to reconnect.