The channel is not alive on some aplot/kplot/lplot tests

[germa89]

          For some reason I keep getting ``ansys.mapdl.core.errors.MapdlConnectionError: The channel is not alive.`` on some tests:

@pytest.mark.parametrize(
    "plot_func,entity,gen_func,arg1,arg2",
    [
        ("vplot", "VOLU", "block", (0, 1, 0, 1, 0, 1), (1, 2, 1, 2, 1, 2)),
        # Uncommenting the following lines raise an exception for channel not
        # alive. See #3421
        # ("aplot", "AREA", "rectng", (0, 1, 0, 1), (1, 2, 1, 2)),
        # ("lplot", "LINE", "l", (1, 1, 1), (1, -1, 1)),
        # ("kplot", "KP", "k", ("", 0, 0, 0), ("", 1, 1, 1)),
    ],
)
def test_xplot_not_changing_geo_selection_components(
....

I haven't been able to found a solution, but it seems other tests pass. So I'm going to keep them comment them, and hopefully I can come back in the future.

Originally posted by @germa89 in #3421 (comment)