Maybe there is a CSS code that is causing the problem as by default out theme does not have a big text for paragraphs. I suggest that you use the font manager to make sure you have consistant fonts. Here are the details.
You need to also check the WordPress Dashboard > X/Pro > Theme Options > CSS and make sure there is no CSS causing the big font issue. And finally, there might be a custom code inside the Child Theme if you use one, Try to disable the Child Theme and see if it fixes the issue.
kindly get back to us with the result of the steps above and URL/User/Pass of your WordPress dashboard using the Secure Note functionality of the post to follow up the case if you still have problems.