Try eleminating the depth factor and see if you got the same results.
Once again the mass flow rate doesn't affected by the modelling as it's not a factor in its formula, only the area (m2) or the flow velocity.

Reclaculate your flow rate using the equation of Q = A x V , WHERE A (m2) and V (m3/s)

please don't hesitate to contact me for any related issue .

Thanks & Regards,