Using this plugin with alternative registration forms

Hiya
I’m using Membership 2 Pro registration form.

I added this line to my child theme’s functions.php:
add_action( 'signup_extra_fields', 'tv_bp_avatar_upload_form' );

But unfortunately, this breaks the reg form, and on submit causes it to go back to the pristine state.

https://www.ads-software.com/plugins/buddypress-upload-avatar-ajax/