Dropdown menus not working after embedding webflow site as iframe into Wordpress

My webflow site is working perfectly when viewing it on my subdomain. Ive got some custom code setup to create dropdown menus and filter image results, but Ive embedded the site into my Wordpress website as an iframe and none of it works.

Dropdown menus are not working, some tabs work (built in webflow functionality) but my custom code doesnt seem to be working.

Does anyone have any ideas? The subdomain is a different domain to the actual domain the site is hosted on.

Ive got a console error from webflow:

webflow.6cceef97c.js:1989 Uncaught DOMException: Blocked a frame with origin “https://mysubdomain.com” from accessing a cross-origin frame.

Why is webflow trying to access cross origin? Sorry I cant show the site URL due to it being sensitive.