Let $R$ be a graded ring and let $\frak{m}$ be the maximal ideal generated by all the elements of positive degree. Then, is it true that $R$ is a UFD iff $R_{\frak{m}}$ is a UFD?

If not, then what would be an example of $R_{\frak{m}}$ being a UFD, but $R$ NOT being a UFD?