Groups that are created in PLAXIS green modes were lost when reloading the project. The PLAXIS green modes are Mesh mode, Flow conditions, and Staged construction.
Figure 1. Creating a group of selected objects in Staged construction
This issue is now solved in PLAXIS 2D/3D 2023.2.1.
In the above-mentioned affected versions, the only workaround is to create the necessary groups in Structures mode.
However, for groups that include elements produced/generated after the geometry has been intersected in green mode, this is not applicable.
The workaround for such cases is:
group (Point_1_1 Line_1_1 Line_1_2)