ive done this, not sure if its fixed yet, but looking likely, thank sofy, ill keep you informed :)

Please follow the steps below:

1. Open the class-seo.php file in the /wp-content/plugins/wpforo/wpf-includes/ folder

2. Find the members_sitemap function on the line: 75

3. Replace the function with the following one: 

    public function members_sitemap($paged){
       $paged = absint($paged);
       $sitemap = '';
        if( $paged && $profiles = $this->get_public_profiles($paged) ){
           foreach ( $profiles as $profile ){
                if( $profile = wpforo_member($profile, 'profile_url') ){
                    $sitemap .= $this->sitemap_url($profile);
                }            
         }
        }
        return $sitemap;
    }

Delete all caches and check again. It should work fine. 

There are 17 profiles in my profile site map that are not working properly. GSC tells me this:

Thank you Sofy, I appreciate it. 

There seems to only be issues in the profiles section of the site map I think. 

We're going to check the issue. Please wait a bit.

I'll update the topic asap. 

When i look at the site map, it shows some blank spaces..... 17. so i suppose these are the erro, but how do i fix it?