This paper investigates the quasinormal modes (QNMs) of a spacetime with Lorentz violation, incorporating a cosmological constant, within the framework of Einstein-Bumblebee gravity. The authors find that the interaction of spacetime with an anisotropic bumblebee field introduces distinct contributions to the axial and polar sectors of vector perturbations, leading to the breaking of isospectrality typically observed in vector modes. Numerical evidence strongly indicates isospectral breaking in the vector modes of Einstein-Bumblebee black holes, characterized by a pronounced breakage in the real part of the frequencies, while the imaginary component remains relatively unaffected. This breaking of isospectrality suggests the presence of two different waveforms in the ringdown phase of black holes, which could provide a potential signal of quantum gravity effects detectable in current gravitational wave experiments. The study uses the matrix method and the continued fraction method to calculate QNM frequencies and confirms the accuracy of the results by fitting the waveforms. The findings highlight the impact of Lorentz violation on the spectral properties of gravitational perturbations and the potential for detecting these effects in future gravitational wave observations.This paper investigates the quasinormal modes (QNMs) of a spacetime with Lorentz violation, incorporating a cosmological constant, within the framework of Einstein-Bumblebee gravity. The authors find that the interaction of spacetime with an anisotropic bumblebee field introduces distinct contributions to the axial and polar sectors of vector perturbations, leading to the breaking of isospectrality typically observed in vector modes. Numerical evidence strongly indicates isospectral breaking in the vector modes of Einstein-Bumblebee black holes, characterized by a pronounced breakage in the real part of the frequencies, while the imaginary component remains relatively unaffected. This breaking of isospectrality suggests the presence of two different waveforms in the ringdown phase of black holes, which could provide a potential signal of quantum gravity effects detectable in current gravitational wave experiments. The study uses the matrix method and the continued fraction method to calculate QNM frequencies and confirms the accuracy of the results by fitting the waveforms. The findings highlight the impact of Lorentz violation on the spectral properties of gravitational perturbations and the potential for detecting these effects in future gravitational wave observations.