Blank first line problem in responses

The first line in the responses to cfml and cfc requests is empty. What is the reason for this?

OS: linux ubuntu
Java Version: 11.0.18
Tomcat Version: Apache/2.4.52 (Ubuntu) - Tomcat/9.0.71
Lucee Version:

Before concluding that Lucee is causing this, consider first that your application.cfc or application.cfm file may have code causing it.

A way to prove if that’s so would be to create a new folder, with an empty application.cfc, and a .cfm page outputting some text, and see if running THAT shows the blank line. If not, then clearly it’s not lucee itself causing it.

Let us know what you find.