I found this reproduce-able in blender 3.5 and 4.0.2
For a project I'm working on I need to be able to programmatically assign a vertex group which can be used in later modifiers to geometry I'm generating using Geometry Nodes. Specifically the Curve to Mesh node.
I found that with a regular mesh this method works fine and I can add for example a Displace modifier with the "Group" Vertex Group as an input and it works as expected.
With the mesh generated by two curves however, the group does not show up in weight paint mode nor does it behave as expected with other modifiers despite being assigned with the same Geometry Nodes tree. Note that pictured is the Geometry Nodes which generate the mesh which combines with the original geometry to preserve the Vertex Group (There are no vertices on the original object.), the nodes that assign Fac to Group are identical to the one pictured above. Also note that in both instances the Spreadsheet shows that there are values for each vertex under "Group".
I'm failing to see why these two instances would behave differently especially when they appear to be the same in the spreadsheet. Is there something I've missed that I need to do to get the curve to mesh object to behave like the regular mesh?