Flux units in surface reaction interface module, and modeling of surface diffusion in axi-symmetric system

Hi,
I am trying to model a bulk - surface reaction-diffusion system (diffusion in the solution, diffusion on the surface, and adsorption/desorption which couples the two together).
The system has a cylindrical symmetry so I want to solve it in an axi-symmetric configuration, and I have two questions regarding the implementation of such system:
1. Initially I constructed the system similarly to the example of Transport and Adsorption case study (Model Library > COMSOL Multiphysics > Chemical Engineering>Transport and Adsorption) which is quite similar. In this case the surface is modeled using a General Form Boundary PDE (gb). I found out that the surface concentration was not solved correctly, and I suspect it is related to the axial symmetry.
Did anyone encountered such a problem?
Does general form PDE work with 1D axisymmetric configuration?

2. I rebuilt the model with surface reaction interface instead of general PDE, and this indeed gives a correct solution for the surface concentration.
I want to check a flux on a point along the surface using the total flux magnitude in the post processing (chsr.tfluxMag_). However, it reports it with the weird units [ mol^2/(m^3*s) ] ,which are definitely not flux units.
The value is also not in agreement to the predicted flux (in fact it is the correct flux*constant).
What is the "flux" which is given there?
Is there another way to calculate the exact flux in this interface?

Thanks!
Henry