In this paper, we study an expected utility portfolio optimization problem involving consumption and robustness analysis for an incomplete market investor. We employ the preferable proportion-to-volatility market price of risk for this analysis in the setting of a 4/2 stochastic volatility model. Due to the non-affine nature, the solution for the value function involves confluent hypergeometric functions similar to those needed for option pricing within the 4/2 model. The paper explores the cases where closed-form solutions are available, providing complementary numerical analyses.