Fredi's girth conjecture for the algebraic bipartite graph D(k,q)

Let $D(k,q)$ be the algebraic bipartite graph proposed by Lazebnik and Ustimenko, where $k\geq 2$ and $q=p^m$ is a prime power. Fredi's conjecture. $D(k,q)$ has girth $k+5$ for all odd $k$ and all $q\geq 4$. The graph $D(k,q)$ is edge-transitive and has girth at least $k+4$; determining its exact girth is relevant to extremal graph theory and related applications. The conjecture is attributed to Fredi (1995), and its resolution is not specified in the source.