It appears that referer headers are sent after clicking on a link even when the anchor has the rel="noreferrer" attribute set (see HtmlAnchor.java:174).

Please add a check for the rel attribute of anchors (forms can have them too) and do not set the referer header when its value is noreferrer.

More info: https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/rel