I’ve experienced something somewhat similar that may help shed some light on the problem.
When I have a text item and I try to use quotes to signify feet and inches, ’ and " respectively. What I discovered is that the mac, by default sets those to be “smart quotes.” That means you get curly quotes instead of the straight quotes that are used to signify inches and feet. This doesn’t seem like a problem until you export that text from Rhino. The system doesn’t quite recognize what those mean, so you end up with random characters in the exported file that are a stand in for those curly quotes. Now, if I copy a straight quote and paste it, it exports just fine.
What I’m guessing is that you are experiencing a similar element of the glitch. Your accents are “curly” on the mac, or an equivalent, and the Rhino export isn’t understanding it correctly. One thing to try would be looking for a simplified character with the accent you need and copying and pasting that in instead of typing it directly. The other thing you can do on the mac is go to System Preferences > Keyboard > Text > Deselect “Use smart quotes and dashes.” That also fixes the functionality.