Free boundary minimal annuli in $S_{+}^2\times S^1$

Let $M$ be a compact 3-dimensional Riemannian manifold with nonnegative Ricci curvature and a nonempty boundary $\mathrm{\partial }M$. Fraser and Li \cite{Fraser&Li} established a compactness theorem for the space of compact, properly embedded minimal surfaces of fixed topological type in $M$ with a free boundary on $\mathrm{\partial }M$, assuming that $\mathrm{\partial }M$ is strictly convex with respect to the inward unit normal. In this paper, we show that the strict convexity condition on $\mathrm{\partial }M$ cannot be relaxed.