Let $A$ and $B$ be two full column rank real matrices of dimension $n \times m$, where $n \ge m$. Let $P$ be an $m\times m$ positive definite matrix.


> **Question:** Does there always exist a symmetric $n \times n$ matrix $X$ such that the following holds?
>
> $$\mathrm{tr}(P(A^\top XB+B^\top X A)) \ne 0$$