Under Linux debugging serial port, found that when using cutecom is opening a serial port ttyXRUSB5, when open the device, the X becomes lower case X, opening a serial port is not successful,

No matter how to input, it is the case, but open ttyXRUSB4 ttyXRUSB6 and other equipment when there is no such a situation, and use minicom can successfully open the

TtyXRUSB5 and can send and receive data, is very strange, the inductive interest Daniel can be solved?