splitCurve not producing the expected result

I mean to use splitCurve in python, from the built-in kernel. I use function test_split_rectangle2 below. The output I get is

Entity dim: 0 , tag: 1 , name: p_lb, coordinates: [ 0. -1.  0.]
Entity dim: 0 , tag: 2 , name: p_lt, coordinates: [0. 2. 0.]
Entity dim: 0 , tag: 3 , name: p_rb, coordinates: [ 1. -1.  0.]
Entity dim: 0 , tag: 4 , name: p_rt, coordinates: [1. 2. 0.]
Entity dim: 0 , tag: 5 , name: psplit1, coordinates: [0.  0.5 0. ]
Entity dim: 1 , tag: 2 , name: l_t, end points: [2 4]
Entity dim: 1 , tag: 3 , name: l_r, end points: [4 3]
Entity dim: 1 , tag: 4 , name: l_b, end points: [3 1]
Entity dim: 1 , tag: 5 , name: , end points: [1 2]
Info    : Writing 'rectangle_split.msh'...
Info    : Done writing 'rectangle_split.msh'

Before splitCurve I have 4 lines forming a rectangle, with tags 1-4. After splitCurve (which aims at splitting line 1) I still have 4 lines, replacing line 1 with line 5 (same end points). I guess I might be misinterpreting the way to use splitCurve, and I didn't find any example.

Any hint is welcome! Thanks

def dump_entity(e):
    """
    @brief Dump information on a (geometrical) entity
    """
    edim = e[0]
    etag = e[1]
    gm = gmsh.model
    ename = gm.getEntityName(edim, etag)
    print('Entity dim:', edim, ', tag:', etag, ', name:', ename, end='')
    if (edim == 0):
        coords = gm.getValue(0, etag, [])
        print(', coordinates:', coords)
    elif (edim == 1):
        # downadj = getAdjacenciesDownward(edim, etag)
        # print(', end points:', downadj)
        eadj = gm.getAdjacencies(edim, etag)
        print(', end points:', eadj[1])
    elif (edim == 2):
        # downadj = getAdjacenciesDownward(edim, etag)
        # print(', edges:', downadj)
        eadj = gm.getAdjacencies(edim, etag)
        print(', edges:', eadj[1])
    else:   # TODO: also define what to do for edim=2
        print()
    return (edim, etag, ename)

def test_split_rectangle2():
    import gmsh
    
    # Initialize Gmsh
    gmsh.initialize()
    gm = gmsh.model
    
    # Create a new model
    gm.add("rectangle_split")

    # Rectangle corners
    bbox = [[0,1], [-1, 2]]
    # Mesh resolution
    res = 0.2

    # Setup a dict for assigning dynamically named variables
    my_locals = {}
    
    # Use the built-in kernel
    kernel = gm.geo

    # Create points
    lr_list = ['l', 'r']  # left/right
    bt_list = ['b', 't']  # bottom/top
    p_list = []
    for ix in range(2):
        for iy in range(2):
            # Create a point (vertex)
            p = kernel.addPoint(bbox[0][ix], bbox[1][iy], 0.0, res)
            var_p = f'p_{lr_list[ix]}{bt_list[iy]}'
            my_locals[var_p] = p
            gm.setEntityName(0, p, f'{var_p}')
            # Collect points in the edge
            p_list.append(p)

    # Create lines
    l_l = kernel.addLine(my_locals['p_lb'], my_locals['p_lt'])
    l_t = kernel.addLine(my_locals['p_lt'], my_locals['p_rt'])
    l_r = kernel.addLine(my_locals['p_rt'], my_locals['p_rb'])
    l_b = kernel.addLine(my_locals['p_rb'], my_locals['p_lb'])
    l_list = []
    for var2 in ['l', 't', 'r', 'b']:
        var = f'l_{var2}'
        val = locals()[var]
        gm.setEntityName(1, val, f'{var}')
        l_list.append(val)

    # Try splitting a line
    # Synchronize the model
    kernel.synchronize()
    # Add point
    coords = gm.getValue(1, l_l, [0.5])
    psplit1 = kernel.addPoint(*coords)
    gm.setEntityName(0, psplit1, f'psplit1')
    kernel.synchronize()
    c = kernel.splitCurve(l_l, [psplit1])
    kernel.synchronize()

    # Print entities
    entities = gm.getEntities()
    for e in entities:
        (edim, etag, ename) = dump_entity(e)

    # Save the mesh to a file
    gmsh.write("rectangle_split.msh")
    
    # Finalize Gmsh
    gmsh.finalize()

    return