Let \(n \ge 8\) be even, and let \(G = \langle x, y \mid x^2 = y^{n/2}, y^n = 1, yx = xy^s \rangle \) , where \(s^2 \equiv 1 \pmod n\) and \(s \not \equiv \pm 1 \pmod n\) . In this paper, we provide the precise values of some zero-sum constants over G, namely the small Davenport constant, \(\eta \) -constant, Gao constant, and Erdős-Ginzburg-Ziv constant. In particular, the Gao’s and Zhuang-Gao’s Conjectures hold for G. We also solve the associated inverse problems when \(n \equiv 0 \pmod 4\) .