Hi Nicole,
To begin with, everything in an HTML document is a node, and once your node count in your HTML exceeds 800, a warning will be raised.
To put that into perspective – generatepress.com has less than 20
nodes.
Here are some recommendations to resolve this: https://www.corewebvitals.io/pagespeed/fix-avoid-excessive-dom-size-lighthouse
Leo’s suggestion to disable plugins is meant to check if other plugins are adding high amounts of nodes to your HTML. Another way to check this is by using a Staging site so you can disable plugins safely.
An alternative would be to move other stuff on this page to another page. Adding a WordPress Page Break block should allow you to do this. Reference: https://wordpress.com/support/wordpress-editor/blocks/page-break-block/
Hope this clarifies!