Laser does not cut in one run but pauses in every corner

[synonym9]

My friend got a huge, chinese Laser-Cutter.
I wanted to cut some plexy which works pretty well BUT, the programm (Lasercut 6) stops before every small bend and contious after it the bend.
On the monitor of the controlling PC we saw the cut-direction-arrows show in different directions, we corrected this so all arrows show in the same direction now but still not difference.
Some people in the CAD-forum told me I need to combine the splines in the DXF-File...we did that to....no difference.
Meanwhile we tried to cut out a simple font and found out the same problem occurs now even there (which was working before). So some setting seems to be changed.
Can you guys help me to find it so the laser cuts through the entire plexi on one run.

Thanks in advance

[synonym9]

Here some pictures