Keyword issue for reaction overpotential

[Saketh1729]

While performing my simulation, I noticed that the reaction overpotential given by the key 'X-averaged positive electrode reaction overpotential [V]' is not the same as the reaction overpotential that appears in the terminal voltage equation.

I checked this by using the SPM model with the Prada2013 parameter set. I extracted the corresponding bulk and surface stoichiometry and mathematically computed the reaction overpotential of each electrode, along with all the other corresponding terms, to determine the final terminal voltage.

The mismatch is shown below. This mismatch occurs even though the exchange current density is the same, and the terminal voltage is the same as well.

I was wondering if I was using the wrong keyword. Can anyone please shed some light on this?