Unwanted mesh line in spherical plot

Question

I am trying to create a spherical colour plot on which the mesh will rotate with manipulating the \phi1 variable. I read this solution and gave it a try with the following code:

Manipulate[
  SphericalPlot3D[1, {θ, 0, π}, {ϕ, 0, 2 π}, 
    ColorFunction ->
      Function[{x, y, z, θ, ϕ}, 
        ColorData[{"Rainbow", {-1, 1}}][Sin[θ] Sin[ϕ - ϕ1]]], 
    ColorFunctionScaling -> False,
    PlotStyle -> Opacity[0.8],
    ImageSize -> 750,
    PlotRange -> {{-1.3, 1.3}, {-1.3, 1.3}, {-1.3, 1.3}}, 
    Mesh -> {8, {ϕ1, π + ϕ1}},
    MeshStyle -> {Black, Opacity[0.5]},
    Boxed -> False,
    Axes -> False],
  {{ϕ1, 0.4}, 0, 2 π}]

The result is mostly satisfactory, except for the extra mesh line at $\phi=0$, which does not rotate with the other mesh lines when $\phi1$ is changed in manipulate.

My question: how do I remove the stationary mesh line, or make it rotate with the other mesh lines properly?

Answer 1

Add the option BoundaryStyle -> None to SphericalPlot3D to get