Medium Online Video not working though defined in CSL

[AnsgarLichter]

I am using the IEEE style and have included its CSL directly:

set cite(../bibliography/ieee.csl)

Now I am including my .bib file as expected - including the recording of a conference talk as source:

@misc{ConferenceTalk,
  author = {{Conference}},
  title = {Talk},
  url = {https://google.com},
  urldate = {04.06.2024},
  medium = {Online Video},
}

According to my CSL (see full version at ieee.csl) this should be rendered as [Online Video] in the literature section:

<macro name="access">
    <choose>
      <if type="webpage post post-weblog" match="any">
        <!-- https://url.com/ (accessed Mon. DD, YYYY). -->
        <choose>
          <if variable="URL">
            <group delimiter=". " prefix=" ">
              <group delimiter=": ">
                <text term="accessed" text-case="capitalize-first"/>
                <date variable="accessed" form="text"/>
              </group>
              <text term="online" prefix="[" suffix="]" text-case="capitalize-first"/>
              <group delimiter=": ">
                <text term="available at" text-case="capitalize-first"/>
                <text variable="URL"/>
              </group>
            </group>
          </if>
        </choose>
      </if>
      <else-if match="any" variable="DOI">
        <!-- doi: 10.1000/xyz123. -->
        <text variable="DOI" prefix=" doi: " suffix="."/>
      </else-if>
      <else-if variable="URL">
        <!-- Accessed: Mon. DD, YYYY. [Medium]. Available: https://URL.com/ -->
        <group delimiter=". " prefix=" " suffix=". ">
          <!-- Accessed: Mon. DD, YYYY. -->
          <group delimiter=": ">
            <text term="accessed" text-case="capitalize-first"/>
            <date variable="accessed" form="text"/>
          </group>
          <!-- [Online Video]. -->
          <group prefix="[" suffix="]" delimiter=" ">
            <choose>
              <if variable="medium" match="any">
                <text variable="medium" text-case="capitalize-first"/>
              </if>
              <else>
                <text term="online" text-case="capitalize-first"/>
                <choose>
                  <if type="motion_picture">
                    <text term="video" text-case="capitalize-first"/>
                  </if>
                </choose>
              </else>
            </choose>
          </group>
        </group>
        <!-- Available: https://URL.com/ -->
        <group delimiter=": " prefix=" ">
          <text term="available at" text-case="capitalize-first"/>
          <text variable="URL"/>
        </group>
      </else-if>
    </choose>
  </macro>

The result is:
Conference, “Talk.” [Online]. Available: https://google.com/

My expected result is:
Conference, “Talk.” [Online Video]. Available: https://google.com/

If I understand the macro correctly, the variable medium should to the work, but it doesn't.
An alternative is to set the type to motion_picture. I tried to use @video and @movie but this didn't work either.
Does anyone have an idea how I can achieve this?

Is there a possibility to add the relevant minutes of the conference's recording as a note?
I didn't find a suitable variable in the CSL.