@ferdinand I figured this issue out so you can mark this as solved/closed. Thank you.

@ELJeffery
The image:

For updating the changed UVWs I am using:

# Update UV data in Cinema 4D using updated data from RizomUV
def update_uvs_in_cinema4d(doc, obj, poly_sizes, poly_uvw_ids, updated_uvws):
    # Retrieve the active document and object once
    doc, obj = get_active_object()
    if not obj or not isinstance(obj, c4d.PolygonObject):
        gui.MessageDialog("No Polygon Object selected.")
        return

    # Get the Polygon Translation Map
    poly_trans_map = obj.GetPolygonTranslationMap()
    polygon_count, ngon_map = poly_trans_map

    # Detect if there are ngons by checking if the ngonMap contains repeated values
    all_polygons = obj.GetAllPolygons()
    has_ngons = len(set(ngon_map)) != len(ngon_map)
    ngon_count = obj.GetNgonCount()
    print("Number of polygons including polygons inside any ngons: ", len(all_polygons))
    print("Number of polygons including ngons: ",polygon_count)
    print("Number of ngons: ",ngon_count)
    print("Number of internal ngon edges: ",len(ngon_map) - len(set(ngon_map)))

    uvw_tag = obj.GetTag(c4d.Tuvw)
    if not uvw_tag:
        print("No UVW Tag found.")
        return

    doc.SetMode(c4d.Mpolygons)

    handle = c4d.modules.bodypaint.GetActiveUVSet(doc, c4d.GETACTIVEUVSET_ALL)
    if handle is None:
        c4d.CallCommand(170103)  # Open UV editor
        if c4d.API_VERSION >= 22000:
            c4d.modules.bodypaint.UpdateMeshUV(False)

        handle = c4d.modules.bodypaint.GetActiveUVSet(doc, c4d.GETACTIVEUVSET_ALL)
        if handle is None:
            raise RuntimeError("No Active UVSet")

    uv_index = 0
    assembled_uvws = []
    adjusted_uvws = adjust_uvs(updated_uvws)  # Ensure UVs are normalized correctly

    for poly_idx, poly_size in enumerate(poly_sizes):
        uv_dict = {}
        uv_indices = poly_uvw_ids[uv_index:uv_index + poly_size]
        uv_index += poly_size

        # Handle triangles
        if poly_size == 3:
            uv_dict = {
                'c': c4d.Vector(adjusted_uvws[uv_indices[0] * 3], adjusted_uvws[uv_indices[0] * 3 + 1], adjusted_uvws[uv_indices[0] * 3 + 2]),
                'b': c4d.Vector(adjusted_uvws[uv_indices[1] * 3], adjusted_uvws[uv_indices[1] * 3 + 1], adjusted_uvws[uv_indices[1] * 3 + 2]),
                'a': c4d.Vector(adjusted_uvws[uv_indices[2] * 3], adjusted_uvws[uv_indices[2] * 3 + 1], adjusted_uvws[uv_indices[2] * 3 + 2])
            }

        # Handle quads
        elif poly_size == 4:
            uv_dict = {
                'd': c4d.Vector(adjusted_uvws[uv_indices[0] * 3], adjusted_uvws[uv_indices[0] * 3 + 1], adjusted_uvws[uv_indices[0] * 3 + 2]),
                'c': c4d.Vector(adjusted_uvws[uv_indices[1] * 3], adjusted_uvws[uv_indices[1] * 3 + 1], adjusted_uvws[uv_indices[1] * 3 + 2]),
                'b': c4d.Vector(adjusted_uvws[uv_indices[2] * 3], adjusted_uvws[uv_indices[2] * 3 + 1], adjusted_uvws[uv_indices[2] * 3 + 2]),
                'a': c4d.Vector(adjusted_uvws[uv_indices[3] * 3], adjusted_uvws[uv_indices[3] * 3 + 1], adjusted_uvws[uv_indices[3] * 3 + 2])
            }

        # Handle ngons (polygons with more than 4 vertices)
        elif has_ngons:
            # Sort the vertices properly and create the UV dict dynamically
            alphabet = 'abcdefghijklmnopqrstuvwxyz'
            for i in range(poly_size):
                # Make sure to use the correct UV order
                key = alphabet[i] if i < len(alphabet) else f'v{i}'  # Handle large ngons
                uv_dict[key] = c4d.Vector(
                    adjusted_uvws[uv_indices[i] * 3],
                    adjusted_uvws[uv_indices[i] * 3 + 1],
                    adjusted_uvws[uv_indices[i] * 3 + 2]
                )

        assembled_uvws.append(uv_dict)

    handle.SetUVWFromTextureView(assembled_uvws, True, True, True)
    bodypaint.FreeActiveUVSet(handle)
    c4d.EventAdd()

My problem is, it works with a mesh that is only quads and tris or any combination thereof, but if the mesh contains any ngons then I get this result:

I am trying to post an issue I am having with some python code but I keep getting:

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