If I insert an external Wikipedia URL in an 's href-attribute (let's say https://de.wikipedia.org/wiki/Foo (without trailing slash)), it redirects me to https://de.wikipedia.org/wiki/Foo/ (with trailing slash).
Unfortunately Wikipedia pages seem not to be reachable with a trailing slash, so I always refer to a 404 page when I try to link a Wikipedia page.
I'm not sure if the automated trailing slash adding is a Wordpress core functionality or if it's done by a plugin.
I'm looking for a way to either turn that functionality off completely, or just for wikipedia.org.