While this can be desirable for controlling page formatting and limiting the need for students to link outside the Moodle site, it can also result in cluttered pages and slow page load times. To force Moodle to display a link rather than an embedded video, modify the link to include the text "embed=no&;", as shown below.

Source link:
https://www.youtube.com/watch?v=VnuXUeEvspY

In the Moodle text editor switch to HTML editing mode (More Buttons > HTML), and place the no embed flag between "watch?" and "v=", like so:

https://www.youtube.com/watch?embed=no&;v=VnuXUeEvspY

This will force Moodle to present the linked text as text, rather than converting it to embedded video.