If you double click on an element that was created with SOFiPLUS(-X), a dialog box will open with which you can modify the element. When several elements are selected, the little dialog quick properties will appear.
In this case there are several options to get the elements modified:
Mark several elements and choose the command to modify via the sidebar.
Double click only one element and pick the other elements afterwards.
Work via the AutoCAD properties dialog.
Modify the entry in the quick properties dialog.