I recently published my site and there is a visible difference from the way it displays when I would preview my site during the build and now that I have actually uploaded it to my FTP. I labeled pages with the breakpoint width so I know it is still using the same breakpoint, but my header and text are significantly larger on the published site. I'm not sure if anyone else has had this issue or knows what might be causing it. I have attached the images below. It is a little difficult to tell the size difference from the photos but it is significant. I have checked everything with inspect and the font sizes say they are the same.
This is the image from the site when I preview it.
This is the image from the site when I go to the published version.
Not sure why this is happening but hope someone can help.
On your businesscatalyst site it looks like this at 1400 to 1900. It looks ok on the "normal" site.
And from approximately 1280 and smaller you have still set your leave to responsive in width and height, but text doesn´t respond to it same way. I would set it to resize "none" and change size from breakpoint to breakpoint.
I also cannot reproduce your other issue with different sizes.