Offset closed curves/polylines not working

Hi, I am unable to offset closed curves/polylines at present. This used to work, but is not any longer. In this image, the one on the left is a rectangle and the one on the right is a polyline. In both instances, offsetting at corners is erroneous. Can someone point me to a fix for this?
Many thanks

Hello- check the command line for the Trim=Yes/No option.