icon entry in feed not used

In this feed, I set the icon entry, but it does not show in ReadYou reader. Other feeds mysteriously have an icon, even though there is no XML entry specifying an icon resource.

<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <id>urn:uuid:1cf733d8-e3b2-4871-a0c1-c76cc08860eb</id>
  <title type="text">This is a Title</title>
  <subtitle type="text">This is a Subtitle</subtitle>
  <updated>2025-02-14T12:07:09.671941+01:00</updated>
  <author>
    <name>John Doe</name>
    <uri>mailto:johndoe@example.org</uri>
  </author>
  <category term="blogposts"/>
  <link href="https://example.org/feed.atom" rel="self" type="application/atom+xml"/>
  <icon>https://example.org/favicon.ico</icon>
  <rights type="text">Copyright (C) John Doe 2025</rights>
  <entry>
    <title type="text">Hello World</title>
    <updated>2025-02-14T12:07:10+01:00</updated>
    <id>urn:uuid:073e838e-1f82-49ee-8c9b-d0ba8f5359e9</id>
    <content type="xhtml">
      <div xmlns="http://www.w3.org/1999/xhtml" style="white-space: pre-line;">Hello World</div>
    </content>
  </entry>
</feed>

Reproduce the issue with the provided Atom feed and inspect the feed parsing and icon display entry points in the Android application. Compare this feed with feeds that currently show an icon, then verify that the Atom icon is displayed while existing fallback behavior still works.