Import File for Site Library

Hello, when attempting to import the Merch demo content I get a 400 error. In the inspector under console the error is:

/wp-admin/admin-ajax.php:1 Failed to load resource: the server responded with a status of 400 ()

My hosting is through Wordpress and they're looking into the issue but are asking if I can get an import file with the Merch content?

I know there are a million forum posts about the 400 error and I've tried everything.

Thanks