Font size still looks the same on my end. I agree with Natalie Trott that it might very well be a mouse wheel change. If you go to the menu options in our browser look for your "zoom" settings.
If you need help with your specific browser this post might help.
https://support.appmachine.com/hc/en-us/articles/203645996-Changing-the-Zoom-Level-of-your-Browser
The post is older, but I think zoom settings haven't changed too much in popular browsers. It's worth taking a look, or doing a quick search for "zoom settings {insert your browser name} browser" If that's not it, I'm happy to trouble shoot more with you.