Unable to embed YouTube Links in Main Site

Hi there,

This is my first time developing with WordPress and I have been stuck on an issue that does not make sense to me.

I am able to embed YouTube links in my posts and the embedded links show up as expected, in a play window. I embed these links via a column block and embed the YouTube video via the following link:

The post displays the YT video as expected.

However, when I go back to the main page of my site, where all my posts are displayed, I do not get the preview window. Instead, I get the raw YouTube link: https://www.youtube.com/watch?v=0HdzTvH8mvw

How can I get the YT video play window to display instead of the raw YouTube link on the main site page. I am using the Core Blog theme, but I have Live Previewed a lot of themes, and they are all doing the same thing. Is there no way to get the YouTube link to render as a play window on the main site page?

The page I need help with: [log in to see the link]