Youtube embeds are not working

I’ve tried to add a youtube link to a post but it seems the frontend is missing the lazyYT javascript to actually start the player embed. The html correctly includes the relevant code, but it’s dormant because of the lack of appropriate javascript. See below:

before embed

https://youtu.be/cWlYe0CE2iU

after embed

This is what I see in the firefox inspector:

image