Hi there,
is the Post Title font going to be different to a font you have selected in the Customizer > Typography > Heading settings?
For type samples add this to a page/post:
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
<h1>H1 Heading The quick brown fox jumped over the lazy dog</h1>
<h2>H2 Heading The quick brown fox jumped over the lazy dog</h2>
<h3>H3 Heading The quick brown fox jumped over the lazy dog</h3>
<h4>H4 Heading The quick brown fox jumped over the lazy dog</h4>
<h5>H5 Heading The quick brown fox jumped over the lazy dog</h5>
<h6>H6 Heading The quick brown fox jumped over the lazy dog</h6>
<blockquote>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat..</blockquote>
<a href="#" class="button">button</a>