Planar grid Ramsey property
Prove or disprove that every 2-coloring of the Euclidean plane contains a monochromatic unit-copy of $P_n\square P_n$ for every positive integer $n$.
References
Is it true that $2 \xrightarrow{2} P_n\square P_n$ for every $n \in $?
— Ramsey problems for graphs in Euclidean spaces and Cartesian powers
(2512.15516 - Axenovich et al., 17 Dec 2025) in Question Q_Pn, Section 6.1 (Planar case)