Thank you @Alisha, @Berto2002,
I've done some investigation to understand what is the problem. There are small differences for users depending on what is the Operating System, browser and specific configuration for each. When we changed the font to Roboto, some users had the font rendered a bit different than others and in some cases with a bad resolution.
We are going to change the way we display fonts and use the system font. It will be a Sans type, making it easy to read and optimized for each operating system and browser.
I hope this will improve the experience for everyone.
Our next build will include this change.
Thank you again for your patience and feedback.
Daniel