The plugin writes 500 blank lines in the output (e.g. source code, where it can actually cause the code not to be read).

But it destroys the Sitemap.xml (here plugin: https://de.wordpress.org/plugins/google-sitemap-generator/ ) (no longer readable according to XML standard!) and robots.txt also makes no sense.

If it should be revised, it is important to pay attention to this.

Otherwise, because of the Sitemap.xml, better test which Copy-Protect-Plugin works properly!

This works for me: https://wordpress.org/support/plugin/wp-copyright-protection/