Icons do not render in post excerpts

[mlwilkerson]

To reproduce:

1. configure the plugin with default configuration (CDN, Free, Webfont)
2. create a post with the block editor, using shortcodes for the icons (same result if <i> or <span> is used)
3. add a few icons in blocks, small enough content such that the automated excerpt would include the region of content that has the icons
4. use a theme that lists post excerpts on the home page, like the default Twenty Twenty-two theme in the standard WP 5.9.3 docker image
5. publish and view that front page

Actual results:

Inspecting the DOM, we see:

<p class="wp-block-post-excerpt__excerpt">beer: star: android: </p>

Expected results: showing the icons