Middle alignment not working in preview

I have created a rectangle acting as a button with text vertically aligned in the middle.

In Axure, the button looks fine:

but when I preview in the browser, the text aligns from the top:

This happens with several other elements too. Am I doing something obviously wrong?

Hi @oliverhardman! It looks like you are using web fonts in your project. Did you do some font mapping in your prototype? If you did, and the issue persists, then can you please email us at support@axure.com your .rp file so we can investigate what’s happening on your side?