There was an update that disabled "internal off" so by default the link now only works for internal users to my org's domain. Any others you must specify manually by domain. That is good for security, bad for usefulness. We would recommend to instead make the default behavior to not list the new EURL publicly instead and allow it to be a public space. Or allow an approval system.
The way it used to work was very helpful when trying to communicate to a larger audience.