Thank you Rokas.
Yes, eventually that was my solution too, although I still have problems when only 2 part of the spline is active. I have started with this idea with A2S and an extra Corner segment but then I try this approach on L1S and it worked.
But what causes that kind of behaviour?
My workflow is the main modelling done in CAD software and imported into MAX. So I kinda have to extract Splines from the model and going through all and do extra connecting some time will be a pain in the ***