The purpose of this paper is to report on an unsuitable behavior of the constrained stochastic gradient (CSG) algorithm for adaptive beamforming in the combination of two events: one or more interference angles-of-arrival are close to the signal angle-of-arrival and the angle spreads of the involved signals are small. In this situation, the CSG algorithm stresses the co-channel interference minimization more than the maximization of the power radiated to the in-cell mobile terminal. We term this phenomenon unbalanced behavior and provide an analytical study to explain it.