restricted pages in rss feed with their full content

During work for adjusting a blog to GDPR I found that with Page Restrict 2.2.8 on WordPress 4.7.5 RSS feeds I subscribe have the full content. So visitors of the site can access login protected pages easily by subscribing to the rss feed. That is certainly not what I intended.

Any way to make sure that in RSS feeds there is *no* content for restricted pages, unless someone authenticated to the RSS feed (not sure whether usuall RSS feed readers can do this, never checked).

For now I am plugin access to feeds via Apache 2.