Communication problem

[wojtulab]

Hello.
I've problem with FirmataStandard sketch. I've just upload the newest firmata version to my Arduino Lenardo on /dev/ttyACM0 port. Upload completed.

My host is: Linux Ubuntu 18.0.4 LTS 4.15.0-42-generic (with Lenardo on board - LattePanda).

Previously uploaded another sketchs (like blink, switiching and others without any problems).

For now my Arduino with Firmata I can't send and receive msg with baud 57600 (default), 9600 and others...

wk@WKALPHA:~$ ls -l /dev/ttyACM0
crw-rw---- 1 root dialout 166, 0 gru 19 16:26 /dev/ttyACM0

Mu user is in lock and dialout group but I can't send and receive msg to arduino.
There is no answer from Arduino using for example:
screen, tty, cu, tail on above port.
The same issue has Arduino IDE on serial monitor.
NodeRed also can't connect to Firmata on /dev/ttyACM0.

By the way Arduino IDE successfully founds my Arduino Leonardo on /dev/ttyACM0 port without any SN.

What is wrong with communication?