vector bundles $\mathcal F, \mathcal G$ such that $\mathcal Hom (\mathcal F, \mathcal G) $ is a direct sum of copies of $\mathcal O_X$

Question

Let $(R, \mathfrak m)$ be a Noetherian local ring of depth at least $2$. Let $X=$Spec$(R)\setminus \{\mathfrak m\}$ be the punctured spectrum and $\mathcal O_X$ be the structure sheaf on $X$ induced from Spec$(R)$.

My question is: For what kind of algebraic vector bundles $\mathcal F, \mathcal G$ on $X$, can we say $\mathcal Hom_{\mathcal O_X} (\mathcal F, \mathcal G)\cong \mathcal O_X^r$ for some integer $r\ge1$ ?

I know that if $\mathcal E$ is a line bundle on $X$ then $\mathcal Hom_{\mathcal O_X} (\mathcal E, \mathcal E)\cong \mathcal O_X$ , and I'm looking for other similar class of vector bundles.

Thanks in advance