On the CAEN V1290N TDC the piggy board for the lower 8 channels is not fixed well to the motherboard.
That prevented to the whole DAQ2 to trigger correctly or even crash every once in a while. Long attempt sot find the error in hard and in software.

I fixed/reattached the piggy board, but be careful with the attached Lemo cables. They might loose the board again (it used to fixed with hot glue).

DAQ2 now also seem to run smoothly.