I think the error is in your Dirichlet bc. You should not use the collapsed subspace, i.e.
is wrong. Instead, you should use the non-collapsed subspace for Dirichlet bc creation, as described in my previous answer, e.g.:
left_dofs = fem.locate_dofs_topological((state_space.sub(0), V), facet_tag.dim, facet_tag.find(1))
bcs = [fem.dirichletbc(u_bc, left_dofs, state_space.sub(0))]
In your current code, because you use the collapsed subspace, you are effectively trying to solve the problem without any Dirichlet bcs, which would understandable give rise to the convergence issue.