Problem with submissions page – Page hangs for editors

Logged in as an admin, the submissions page works fine. But for editors, when you select a form from the dropdown the loading form spinner just gets stuck. This started with a fairly recent update. I’m now on the lastest version and it’s still acting the same (on 2 sites).

In 2017 I had to add this to functions.php so editors could see submissions:

add_filter( 'ninja_forms_admin_parent_menu_capabilities',   'nf_subs_capabilities' ); // Parent Menu
add_filter( 'ninja_forms_admin_all_forms_capabilities',     'nf_subs_capabilities' ); // Forms Submenu
add_filter( 'ninja_forms_admin_submissions_capabilities',   'nf_subs_capabilities' ); // Submissions Submenu
function nf_subs_capabilities( $cap ) {
    return 'edit_posts'; // EDIT: User Capability
}

I’ve tried adding this to solve this recent issue:

add_filter( 'ninja_forms_api_allow_get_submissions', 'nf_define_permission_level', 10, 2 );
add_filter( 'ninja_forms_api_allow_delete_submissions', 'nf_define_permission_level', 10, 2 );
add_filter( 'ninja_forms_api_allow_update_submission', 'nf_define_permission_level', 10, 2 );
add_filter( 'ninja_forms_api_allow_handle_extra_submission', 'nf_define_permission_level', 10, 2 );
add_filter( 'ninja_forms_api_allow_email_action', 'nf_define_permission_level', 10, 2 );

function nf_define_permission_level() {
  
  $allowed = \current_user_can("delete_others_posts");
  
  return $allowed;
}

The above code came from:
https://gist.github.com/New0/06d5b7664a8cfbb256a13bc68de0aa98

I don’t understand why editors cannot see submissions by default. Surely editors (clients) need to see their form submssions. I’ve also seen mention of using the User Role Editor plugin to resolve who can see submssions. Do I really have to install another plugin just for this task?

If anyone knows how to allow editors to see form submssions I’d be very grateful.

Thanks.