mesycontrol process starts but shows no GUI at all.

Around 02:51 we wanted to record leakage currents for PLEIADES. 
The windows of the mesycontrol were not present on the screens. 

We followed the instructions for restart:
-ssh -X into x86l-128 (-X is important, otherwise qt will not be initialized)
-mesycontrol

as a result we see nothing but the terminal is busy, and the process exists. 
We noticed that ssh connection establishes very slow, the terminal after the connection responds to typing with a delay of several seconds(one press 'm', after 1-2 sec that letter appears on 
the screen).
 
htop hanged the terminal entirely without showing a thing. Several minutes before we started htop and 12th thread(processor?) has been fully busy, 100%.

our assumption is that GUI has been closed because computer had not enough resources for sustaining it. We would not expect such a slow response even in terminal. 
Could anybody have a look on x86l-128 and figure out why is it so slow? 

UPD: started mesycontrol around 03:40, until 04:02 nothing happened except first two commands. 
Tried to start it from x86l-124 and everything works fine except that the connection to /dev/tty/USB0 can't be established (because it is occupied by x86l-128?)
So we are not able to read leakage currents.