Sorry if I am not clear, my previous reply about Theme Options > Typography > Root Font Size is solely for the responsive Font Size, it has nothing to do with column layouts. If the Root Font Size option still confused you please read the details here (https://theme.co/changelog/#theme-x-5-1-0).
Basically, you see 5 (XS, SM, MD, LG, & XL) Font Size fields there, right? That represents screen size. So, whatever value you set there that will be your base font size on that certain screen width.
I did take a look on your page, and I don’t understand what is the difference that you’re referring to, please clarify, please provide us a couple of screenshots on it looks on your device and how it looks on your preview because on my end I don’t see any difference. Also, please clear your device browser’s cache, you might have a caching related issue.
Another thing, on the conjunction with Christian’s said above with the broken HTML markup. The URL field on the button should only contain the actual URL, not an entire anchor
<a href> tag.
So if you want to link the button to Gogole page then just put the direct URL
This broken HTML markup even the tiniest bit can affect the layout of your page, please make sure to correct all of those errors, review each of your content. You can use this tool here for checking your HTML markup or better not to use HTML markup at all and style/format your content with the native options provided by the element.