I’m also having issues with Luban 3.15.0 which I naively installed without checking here on the forum first. My issue seems to have to do (1) with circular arcs and (2) with improper clipping of the geometry for the laser paths and in both cases when the geometry comes in as DXF files. In all cases so far, incomplete circles are interpreted fine in the geometry display but the laser paths execute the wrong part of the circle in many cases. Here are two screen shots - the first is of the raw geometry as seen within Luban and the second is the calculated laser path.
On a positive note, the terrible DXF scaling problem in the prior version of Luban seems now to have been fixed. However, problem number 2 is that for geometry that comes close to the x-y extents of the file there appears to be the risk of losing some of the corresponding laser path.
Here are the geometry and laser paths for that case. Note here, too, the lower right corner fillets in both rectangular shapes have been screwed up in the laser path as well as the right edge of the big circle getting clipped in the laser path.