The interior balanced-submatrix conjecture

Let $A\text{ }\in\mathcal{B}_{n}(\mathbb{R})$ be a square balanced matrix. An interior balanced-submatrix conjecture asserts that some interior of $A$, meaning a submatrix of $A$, is also balanced.

This would assert that every square balanced matrix contains a balanced submatrix. The source provides no resolution or further context for this claim.