Hi.
Yes, this time it was running for long period of time before crashing. But it changes all the time. Some time it crashes after an hour and some times it can run longer.
The last crash (after 13h) the MAWI server was not running only the Spacedesk and the monitors were connected . But I will have to double check it ( I am not the only one who operates this system ).
Thanks a lot for your help.