Hello @joserodrigz,
Thanks for writing in! Please revert back to Pro 5.1.5 version because there is an on-going issue with the fonts in the latest release. Our developers are already looking into the issue. A patch update will be rolling out anytime soon.
We highly suggest that DO NOT update the live sites right away. Always to keep in mind that you need to create a staging site and then do the WordPress core updates, Theme and Plugins update first in the staging area so that when there are issues or conflict, you can troubleshoot in the staging area without disrupting the live site. Once everything in the staging area is working 100%, you can then push all those updates to the live site. If this is the first you header about staging sites or staging area, please check out this article:
Best Regards.