Mutual-visibility number conjecture for Cartesian products of paths and cycles

Let $P_s$ be the path on $s$ vertices and $C_t$ the cycle on $t$ vertices, and let $cmu(G)$ denote the mutual-visibility number of a graph $G$. Mutual-visibility number conjecture. If $t cge 12$, then

$$cmu(P_s cBox C_t) = cmin\{3s, 2t\}.$$

The equality is known in the range $12 cle t cle 17$ from the constructions and computational results discussed in the paper, while the assertion for all $t cge 12$ remains open.